Tropical Fish Forum

Tropical Fish Keeping Help and Advice => Fishtank Filtration and Cycling => Topic started by: jaypeecee on December 29, 2018, 02:48:16 PM

Title: What is a safe maximum nitrate level for freshwater fish?
Post by: jaypeecee on December 29, 2018, 02:48:16 PM
Hi Folks,

I have been trying to establish a safe maximum nitrate level for freshwater fish. You'd think it would be easy to do just that but figures on the internet vary wildly - from 20ppm to several hundred ppm! I keep my tanks at less than 20ppm but that's partly to prevent algae outbreaks (along with phosphate levels).

Can anyone answer this question or point me to reliable sources of information on this topic?

Thanks in advance.

JPC
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Sue on December 29, 2018, 03:54:36 PM
Someone who writes for Seriously Fish and is also a member of another forum has stated on that forum that the upper safe limit for nitrate is 20 ppm as measured by our test kits. He has given this source on that other forum https://www.researchgate.net/publication/8063535_Nitrate_Toxicity_to_Aquatic_Animals_A_Review_With_New_Data_for_Freshwater_Invertebrates
Note that the link uses the other way of measuring nitrate and the numbers in there should be multiplied by 4.43 to get them to the unit used by our test kits.

He also says that Dr Neale Monks recommends nitrate below 20 ppm.


Levels higher than this will shorten the lifespan of most fish and will cause illness in a few species - high nitrate has been cited as one cause of hole in the head in cichlids. High nitrate does not kill or harm fish quickly like ammonia and nitrite do.
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: jaypeecee on December 29, 2018, 05:45:48 PM
Someone who writes for Seriously Fish and is also a member of another forum has stated on that forum that the upper safe limit for nitrate is 20 ppm as measured by our test kits. He has given this source on that other forum https://www.researchgate.net/publication/8063535_Nitrate_Toxicity_to_Aquatic_Animals_A_Review_With_New_Data_for_Freshwater_Invertebrates
Note that the link uses the other way of measuring nitrate and the numbers in there should be multiplied by 4.43 to get them to the unit used by our test kits.

He also says that Dr Neale Monks recommends nitrate below 20 ppm.


Levels higher than this will shorten the lifespan of most fish and will cause illness in a few species - high nitrate has been cited as one cause of hole in the head in cichlids. High nitrate does not kill or harm fish quickly like ammonia and nitrite do.

Hi Sue,

Many thanks for the link and Dr Monks' recommendation. I have requested the full version of the linked scientific paper and will read it with interest when it arrives in my Inbox.

JPC
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Hampalong on December 29, 2018, 06:33:00 PM
A few years ago I read a paper - haven’t been able to find it again since - that studied the effects of nitrate - acute and chronic - on various fish, freshwater and marine, and a few other watery lifeforms. The fish species studied weren’t representative and there were only a handful that are aquarium fish, but the study did conclude that some species are harmed by as little as 10ppm (some were far more tolerant, into the hundreds).
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Matt on December 30, 2018, 07:47:07 AM
I must admit that I avoided this issue on my website and simply said the increase in nitrates between weekly water changes should be kept to less than 20ppm...
I also believe it depends on the fish species in question and I also keep cichlids and personally believe the link with hole in the head disease to be true...

The other factors to consider are tap water nitrate can legally be as high as 50ppm in the UK I believe so for some people 20ppm is hard to achieve (though there is always RO water this doesn't just strip out nitrates of course... and is another topic!). Further to this @jaypeecee i believe you are planning on having a planted tank which should mean nitrates are lower as the plants will consume them - so you could theoretically start the week with higher nitrates than ending the week. However, you must also consider that complete and/or macro plant fertilisers contain nitrates so you could well be adding them! I actually has a situation where I temporarily had very high nitrates as a result before I spotted it at my next set of water tests (like some others here I didn't do these very regularly nowadays but this has got me started again). It were the shrimp that seemed most suseptible most quickly to the high nitrates. I was dosing a complete liquid fertiliser at the recommended dosage but believe the slow growing nature of most of my plants meant it was not being used up quicker than it was being added. I now dose a combination of a complete fertiliser and a micros only fertiliser to keep my nitrates in check (I dose at levels i have tested to be effective - iron is a good indicator for micro ferts levels and I use nitrate of course as a measure for the macros).
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Littlefish on December 30, 2018, 09:58:02 AM
My tap water nitrates are 40ppm, which is a concern.
In my more heavily planted tanks it is normal to have a slightly lower nitrate reading before a water change, and with some of my more sensitive fish I use a mix of RO & tap.
However, I'm never going to get to <20ppm, unless I move to another region.  :(
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: jaypeecee on December 31, 2018, 12:50:18 PM
I must admit that I avoided this issue on my website and simply said the increase in nitrates between weekly water changes should be kept to less than 20ppm...
I also believe it depends on the fish species in question and I also keep cichlids and personally believe the link with hole in the head disease to be true...

The other factors to consider are tap water nitrate can legally be as high as 50ppm in the UK I believe so for some people 20ppm is hard to achieve (though there is always RO water this doesn't just strip out nitrates of course... and is another topic!). Further to this @jaypeecee i believe you are planning on having a planted tank which should mean nitrates are lower as the plants will consume them - so you could theoretically start the week with higher nitrates than ending the week. However, you must also consider that complete and/or macro plant fertilisers contain nitrates so you could well be adding them! I actually has a situation where I temporarily had very high nitrates as a result before I spotted it at my next set of water tests (like some others here I didn't do these very regularly nowadays but this has got me started again). It were the shrimp that seemed most suseptible most quickly to the high nitrates. I was dosing a complete liquid fertiliser at the recommended dosage but believe the slow growing nature of most of my plants meant it was not being used up quicker than it was being added. I now dose a combination of a complete fertiliser and a micros only fertiliser to keep my nitrates in check (I dose at levels i have tested to be effective - iron is a good indicator for micro ferts levels and I use nitrate of course as a measure for the macros).

Hi Matt,

You are correct in saying that 50ppm nitrate is the UK maximum limit. But, if it's any consolation, the maximum value for my supplier (South East Water) in 2017 was 32ppm. Many aquatics manufacturers produce nitrate removers so achieving less than 20ppm should not be difficult. I use RO/DI water with added minerals so my starting point for nitrates is zero.

My main tank is planted but I choose to use root tabs as the primary source of macro and micro nutrients. I add liquid fertilizer once a week (at most). Then I add trace elements if the plants are beginning to show any deficiencies. Using this combination has eliminated any algae problems, which was an issue when relying only on liquid fertilizers. FWIW, I use Seachem's Flourish range of products. I also use CO2 injection. Seachem Flourish (Comprehensive) has only low N, P and K content. Regarding the measurement of iron as an indicator of the micro nutrients, I find it unreliable. That's because it's rapidly absorbed by the plants. I seem to remember that, after a couple of hours, there was virtually no iron left in the water column!

JPC
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: jaypeecee on December 31, 2018, 01:15:16 PM
My tap water nitrates are 40ppm, which is a concern.
In my more heavily planted tanks it is normal to have a slightly lower nitrate reading before a water change, and with some of my more sensitive fish I use a mix of RO & tap.
However, I'm never going to get to <20ppm, unless I move to another region.  :(

Hi Littlefish,

As mentioned in my reply to Matt, there are lots of products available to remove nitrate from aquarium water. A quick search returned the following:

https://www.swelluk.com/aquarium/treatments-additives-387/phosphate-nitrate-removal-1301/

Good luck!

JPC
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Hampalong on December 31, 2018, 05:38:54 PM
You can also mix with rainwater to reduce nitrates... especially if you have a plentiful supply.
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Littlefish on January 10, 2019, 02:43:02 PM
With the number of tanks I'd have to have a very plentiful supply, and I'm not sure I'd trust the quality of what comes off my roof.  ;D

I've purchased some products from the LFS, and plan to try them out when I have time.
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Littlefish on January 17, 2019, 10:38:13 AM
Well, I decided to treat myself, the fish, and the amphibians.
Recently I bought myself a water change kit (similar to a Python).
Sue mentioned the Pozzani filters in another thread, so I had a look at them. I wouldn't be able to fit the filter cartridge under the sink, and this is a rented property, so couldn't start knocking things around. However, with the hose & connectors from the water change kit, I could attach the filter to the tap. In reviews on several sites a few people say that this filter also has an impact on pH, so I'll have to run some tests before I feel comfortable using the water in the tanks, but the though of getting water with 0ppm nitrates is quite exciting.
They also do a water hardness reduction filter....hmmmm, interesting. I'd have to be careful though as a lot of my gang were chosen as they were more suitable for harder water. May be useful instead of purchasing RO for the other tanks though.
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: jaypeecee on January 18, 2019, 01:36:16 PM
Hi Littlefish,

I did a bit of reading on the internet around the subject of nitrate removal as I am no expert on this subject and I like to understand how things work. It seems that ion exchange resins are used for nitrate removal. The reason the pH drops is apparently because the alkalinity of the water also drops. So, if you have a KH test kit, it may well be worth measuring both pH and KH. It is easy to raise KH if the need arises.

JPC
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Littlefish on January 18, 2019, 05:26:05 PM
Hi @jaypeecee ,

Thanks for the information. I planned to run some water off using the filter and test all parameters before considering how much to use in the tanks. Water here has nitrate levels of 40ppm, and a hardness of 17dH, so I was assuming that I could use a mix of filtered water and tap water to slowly adjust the water in my tanks.
Even my fish that are suitable for hard water shouldn't mind the levels dropping more towards the middle of their range, and I hope to be able to easily introduce the filtered water in the tanks where I use a RO/tap water mix.

I'm also hoping that I may be able to reach some sort of happy medium where I don't have to remineralise the water, even if it means only dropping my nitrates to 20ppm - that would be better than what I have at the moment. I'm looking forward to seeing what I can do with the water to provide my gang with a healthier environment, and hope they will be happy with the end result.

I'll probably also be using the filtered water in the kettle. The reduction in limescale issues should avoid me having to buy a new kettle quite so quickly.  :rotfl:
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Littlefish on January 19, 2019, 03:46:14 PM
Just to report back on the first set of water tests today.

I attached the Pozzani nitrate removal filter cartridge to the tap, and flushed it for at least 2 minutes, as suggested in the instructions. I left it running at a low flow rate while I found my test tubes, lids, and rack.
I took sample of filtered water, then removed the attachment from the tap, and took a sample of tap water.

I tested both samples with the JBL test strips, and with the API Master Test kit. I have attached pictures, which may not be great, but at least you can see the difference between tap and filtered water.
The test strips show lower pH and KH for the filtered water, no difference in GH, and much lower nitrates.
The API tests show lower pH and nitrate for the filtered water.
I could afford a drop in KH, but don't want it to drop too much for fear of it impacting tank water stability. I could always increase KH slightly with baking soda, or use a mix of tap & filtered water.

I also have a filter cartridge to reduce hardness, so my next step is to attach that to the water supply (in line with the nitrate filter), and test the water that comes off that. I'm hoping it will lower GH without lowering KH. Fingers crossed.

Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Littlefish on January 19, 2019, 04:57:54 PM
I attached the water hardness reducing filter cartridge to the nitrate removal cartridge, ran the water for a few minutes, then took a sample to test.

There was still a reduction in pH and KH levels, but not quite as much as with just the nitrite filter. The GH levels plummeted.  :yikes:  All other results seemed about the same as the previous test, including nitrate levels of 0.

I'm going to have a look at mixing filtered and tap water, and see what ratio I need to get the results I'm comfortable with. I'm guessing 50/50 (ish). Then I'll take several samples and test them multiple times to make sure the results are reproducible. This could take a while.  ::)

Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: fcmf on January 19, 2019, 07:34:25 PM
I've been reading this thread with interest and look forward to reading the results of @Littlefish's latest set of research.

I've read elsewhere that another method of reducing nitrates, if high in tap water, is to fill a bucket with water a few days prior to water change day, with an internal filter containing nitrate-reducing media, then use that reduced-nitrates water as the replenishing water. (Poor Littlefish would have hundreds of such buckets constantly in use throughout her house, though, given the vast number of tanks she has.  ;))


Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Littlefish on January 19, 2019, 09:26:27 PM
@fcmf you are correct.  :rotfl:

I did test a small sample of a 50/50 mix of tap and filtered water. It was better than my tap water, but still not ideal, so I'll have a look at some more mixes tomorrow.

I've still got the Seachem De-Nitrate media to go into the filters, and am moving to TNC Lite (no nitrate) for the plant fertiiser. So rather than getting too concerned over the perfect mix of water types, I might just be grateful to be able to lower my nitrates, and be glad that every little change will help.  :)
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Matt on January 19, 2019, 10:14:01 PM
That is quite a dramatic difference!_
Two thoughts for you... rather than do lots of little batches to find the right mix do one bit one to which you add more tap water whistling testing. This will even out any inconsistencies :)
Also I would run the same exercise again in a couple of months to gain an understanding of how quickly the performance of the media degrades. They will still be doing a stirling job I'm sure given those results but you may need to subtly change the ratios to keep the final product steady.
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Littlefish on January 20, 2019, 08:57:20 AM
I agree, it is a dramatic difference.  :o
I don't know why I was so amazed by the results, as all the reviews I'd read indicated that this is what I would see, but I'm always a tad dubious about these things until I see the results for myself.
Currently I have the filters in-line, so I'm going to separate them and look at mixing the water from them in a different ratio, and see what I can do with that.
The tiger barbs are due a clean & water change, so I plan to use some of the water with lower nitrates in that tank, as well as adding the Seachem De-nitrate media to their filter, and moving to the TNC Lite. If I just do it on this tank for now I'll have enough time for daily testing to keep an eye on things, and make sure nothing goes wrong.
I will keep an eye on the filter cartridge performance, as you suggest. With weekly pre-water change testing I usually run a tap water sample as a control because sometimes it's easier to look at colour difference rather than absolute values. It will be just as easy to also run a filter water sample at the same time. With the amount of tank samples I run, one more sample makes no difference.  ;D
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Sue on January 20, 2019, 09:49:36 AM
I am sure I read somewhere that these filter cartridges don't loose effectiveness slowly at the end of their life but go suddenly from working effiecently to nothing. It is definitely worth checking them regularly.
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Littlefish on January 20, 2019, 12:50:40 PM
I'm under the same impression that filter cartridge performance falls off a cliff rather than showing a gradual decline.
I'll see what information I can find about roughly how long the filters last/how much water they will filter, and make sure that I have a spare ready in plenty of time. Saying that, I ordered the current ones directly from Pozzani and they were delivered the next day, so that was great.
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Sue on January 20, 2019, 12:57:46 PM
And the higher the nitrate/hardness, the faster they stop working  ;)
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Littlefish on January 20, 2019, 06:48:02 PM
I'm afraid so, and the filters will be working hard with the water I have here.
From some of the information I've found today it looks as if the nitrite removal filter will do somewhere around 600-800L water, taking it from 50ppm to 0.  With my levels of 40ppm, and with my number of tanks, it won't take long to wear out a filter. Looks as if I'll be getting a replacement in sooner rather than later.  ::)
Still, I won't have to buy RO from MA, and the fish should be better off with this filtered water.  :fishy1:
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Matt on January 21, 2019, 10:20:06 AM
I'd be interested to understand how long you think it will take to 'pack back your investment vs getting RO water?
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Littlefish on January 21, 2019, 01:53:55 PM
That's a difficult one because I don't use RO in all of my tanks, but do plan to use filtered water in all of my tanks.

I buy RO from LFS @ £3.50 per container (20-25L), and use approximately 3 containers a week, mainly on the river tank, and to top up any evaporated water in other tanks. Assuming a 4 week month, I spend around £42 a month on RO to drop the GH down to 14, with no significant impact on the nitrate levels on the river tank.

The nitrate removal filter cartridge and water hardness removal cartridge were £35 each, plus delivery of £5.95. Information I've found indicates the filter will do 600-800L tap water. One chap said his did 600L, starting with nitrate levels of 50ppm, and taking them down to 0. I will be using low nitrate water in all tanks, and expect to use at least 1 filter a month. Individual replacement cartridges are £13.95.

I will not be using the hardness reduction filter cartridge as much, and estimate that I will be using it less than half as much as the nitrate cartridge. Costs are £35 a cartridge (no replacement filters).

So, assuming I wanted to use 1400L/month water with 0 nitrate, and 700L with 0GH, I would use 2 nitrate filters and 1 hardness reduction filter = £90 for first month, then £55 each month after that (including delivery costs for cartridges).

Assuming I wanted 1400L/month RO = £196 a month (not including cost of purchasing containers).

Obviously RO is pure, and the water I get through the filters is not. Also, I've not included the cost of attaching the filters to the water system, which for me was around £25 for a water change kit similar to the Python ones.#

However, if I was just planning on using the water in the river tanks, the calculations would look like this:-
RO water 300L/month = £42 a month = £504 per year.
Filtered water 300L/month = 3,600L/year = £200 per year
Assuming 1 nitrate filter cartridge and 4 replacement filters = £95
Assuming 3 hardness reduction filter cartridges = £105

Sorry the answer has been quite long and rambling. Basically, due to cost I wouldn't have considered using RO in all of my tanks. I also struggle transporting the large containers from the LFS, especially lifting them out of the boot of the car and getting them into the house. Using the recently purchased water change kit made me realise that I could use that for the filters, rather than attach the cartridges to the pipes under the sink, which made looking at reducing the nitrates in my tanks a more reasonable idea. I won't be getting the nitrates to 0 because the filters also impact the KH & pH, but anything less than the 40ppm in my tap water will be better for the fish.


Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Matt on January 22, 2019, 05:51:39 AM
Thanks for taking the time to write that up @Littlefish  :cheers:
That's both interesting and useful to know :)

Fortunately nitrates arnt a problem with my tap water. Hardness can be very unstable though...
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: fcmf on January 22, 2019, 10:54:08 PM
Yes, this is indeed extremely interesting, so thanks for the clear and methodical write-up.  :cheers:
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Stripyjoe on August 22, 2019, 03:10:31 AM
Hey Donna, Sue - bit late (6 months ) but I figured this an appropriate place to post my questions.. as I have some concerns with my Nitrate readings.. hope you recall, I'm (still  ) a 'newbie' and set up  my 3 tanks in quite a rush - the 250L was an 'in-fish' cycle, which appears to have worked - it's the healthiest tank now  in terms of chemos.. 20 ppm nitrates wi' 50% WC  per week - tho' perhaps I shud do lower %age two times a week, so lower nitrate change / less shock..?  ???    But that's not my main concern, - it's my 350L cichlid tank - equivalent of 20 juvis at 3~4 inches, with bio load of 40+ppm nitrates per week.. I  need 50% WC twice a week just to keep up!  I  don' believe I'm over feeding the fish.. I've cleaned the gravel substrate during the WC.. tho' minimum moving of rocks and ornaments - 50%  change is 16 bowls  of water, so it ain' a quick process..  :(    I've trawled thru all the forum related posts, but I don't see any 'Nitrates fix' .. they all say - 'water change' .. I'm impressed wi' wot I see concerning 'BioHome' media.. the aerobic  then anaerobic bacteria path seems to work,  tho', with fast flowing canister filters, I don't see how the anaerobic environment can be achieved.    So, I have not seen - anywhere - in these high Nitrate probs - how to fix it.. I've even got 'live' plants which thankfully grow faster than the cichis eatin' them.. but today I got all the components  together to add 2 x 5L 'Biocenosis Clarification Baskets' - according to Dr Kevin Novak recommendations, more or  less.. which I will add tomorra with my water change.. and I plan to inform you of any 'significant' nitrate reduction  in about 2 months time.. but, why have I not seen any reference to this possible nitrate fix..?  thks..  :: :)
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: dwindstr on August 25, 2019, 04:39:14 AM
Just discovered this topic as I'm new to the forum.  I live in the Oregon, US, but was surprised to learn that people in the UK are living with 50 ppm nitrates out of the tap.  I have zero.  BUT....I have higher ph that I would like for most of my fish.  I got a reverse osmosis system years ago, for my own drinking water, and what I do now is half and half RO and tap water to achieve the right balance.  So might it be worth it for people that have high nitrate PPM out of the tap to invest in an RO system and mix with the tap water? 

I haven't read through the whole thread so if this has already been discussed, forgive me.

Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Sue on August 25, 2019, 10:55:12 AM
A lot of the UK has water that contains nitrate from fertiliser used by farmers. Not all the UK has high nitrate, it's just that 50 ppm has been set as the maximum that's safe for humans. For instance, mine has about 3 ppm.

Also, I have read elsewhere that UK water companies measure nitrate differently from USA water companies. In the UK, it is the actual amount of nitrate (nitrate-NO3) while the USA uses the amount of nitrogen in the nitrate (nitrate-N). This means that levels given by the American method are lower than the levels given by the UK method even though the amount of nitrate is the same. 50 ppm nitrate-NO3 is the same as 11 ppm nitrate-N. (And my 3 ppm nitrate-NO3 converts to 0.67 ppm nitrate-N)



There are a few ways to reduce nitrate before water is added to the tank.
The first, as you say, is to use pure water to dilute it - RO, DI or even rain water. This also removes everything else from the water so areas with soft water end up with even softer water.
Nitrate removing filters such as pozzani filters can be used - these remove just nitrate.
Plants can be used - if water is left in a container with a lot of plants, nitrate can be lowered but not usually removed.
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: jaypeecee on August 25, 2019, 02:24:25 PM
A few years ago I read a paper - haven’t been able to find it again since - that studied the effects of nitrate - acute and chronic - on various fish, freshwater and marine, and a few other watery lifeforms. The fish species studied weren’t representative and there were only a handful that are aquarium fish, but the study did conclude that some species are harmed by as little as 10ppm (some were far more tolerant, into the hundreds).

Hi,

Just looking back over nitrate-related stuff and spotted your post.

So, when discussing nitrate toxicity, what I glean from this is that it is important to distinguish between acute and chronic toxicity.

JPC
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: dwindstr on August 25, 2019, 06:41:48 PM
I have read that UK water companies measure nitrate differently from USA water companies. In the UK, it is the actual amount of nitrate (nitrate-NO3) while the USA uses the amount of nitrogen in the nitrate (nitrate-N). This means that levels given by the American method are lower than the levels given by the UK method even though the amount of nitrate is the same. 50 ppm nitrate-NO3 is the same as 11 ppm nitrate-N.
Just to be clear, when say my tap water contains 0 nitrates, I am not using the local water company as a source, that is simply the result I get when testing for nitrates with the API Master Test Kit commonly used by aquarists in the U.S.  I don't really know what method they are using.
Here is a video of the nitrate test product.  API has a presence in the UK as well as Europe and the US.
<a href="https://www.youtube.com/watch?v=RhoGeIp6t0k" target="_blank">http://www.youtube.com/watch?v=RhoGeIp6t0k</a>
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Sue on August 25, 2019, 07:26:01 PM
That is the most commonly used test kit in the UK as well.


Do you live in an agricultural area? That is the main reason for nitrate in tap water. I am lucky that my water comes from a reservoir with very little agriculture around it so my nitrate is very low.




I know that some Americans are horrified that the UK allows 50 ppm nitrate in drinking water and they say that the maximum allowed in the US is 10 ppm. The different way of measuring it means the two are almost the same.
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: dwindstr on August 25, 2019, 10:11:19 PM
That is the most commonly used test kit in the UK as well.
Do you live in an agricultural area? That is the main reason for nitrate in tap water. I am lucky that my water comes from a reservoir with very little agriculture around it so my nitrate is very low.
I know that some Americans are horrified that the UK allows 50 ppm nitrate in drinking water and they say that the maximum allowed in the US is 10 ppm. The different way of measuring it means the two are almost the same.
Perhaps I'm missing something here.  Are you saying that this API Nitrate Test that is distributed in the UK uses one standard and the very same looking packaged product that's distributed in the US uses the other standard?  If not, then using that test kit should give an equal means of comparison.  If so, have you verified this with API?  It would seem to make the most sense to keep that product's methodology the same across regions, so fish-keepers are not comparing apples with oranges.
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: dwindstr on August 25, 2019, 10:14:35 PM
Do you live in an agricultural area? That is the main reason for nitrate in tap water. I am lucky that my water comes from a reservoir with very little agriculture around it so my nitrate is very low.
I live in Linn County 65 miles due south of Portland.  Linn County calls itself "the seed capital of the world".  Lot's of grass and hay.  And some farms producing cattle, sheep, dairy and fruit.
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Stripyjoe on August 26, 2019, 12:04:03 AM
Hey guys 'n gals - good to see this topic still here - a follow up on my 'personal' nitrates problem, coupla days ago I sorta  had a moan about my continuous 50% water changes in my cichi tank - with my 'fishy-expert' in my local shop - he seems pretty knowledgeable - rattles off all the scientific fish names without hesitation -anyhow,  he asked me how I tested for nitrates - my answer, the API Master test kit -  aaah.. his response - it  is completely 'unreliable' at the higher readings - sorta 30 or 40ppm and upwards..  they no longer use it in their business. He recommended the Tetra Nitrate only  kit ( about £9 ) which I bought. On testing my tanks, now between 2 days and a week since last water changes, they all read close to half of the API test readings, viz: 90L community tank 60 ppm down to 35ppm,   250L community (bigger fish) 25ppm down to 15ppm, the 350L 20-ish cichi tank 40ppm down to 25ppm.. conclusion, I'm gonna keep chkn nitrates in the tanks using the Tetra kit. I was also told that API kit will rarely give a clean zero for ammonia, again my experience - it's always sorta 0.1..but I'll take that.. and lookin' to get individual 'single-chemo' kits in the future. My  reduction in water bill will easily pay for the new kits, lol..  ;D
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: dwindstr on August 26, 2019, 12:15:17 AM
the API Master test kit -  aaah.. his response - it  is completely 'unreliable' at the higher readings - sorta 30 or 40ppm and upwards..  they no longer use it in their business. He recommended the Tetra Nitrate only  kit ( about £9 ) which I bought. On testing my tanks, now between 2 days and a week since last water changes, they all read close to half of the API test readings, viz: 90L community tank 60 ppm down to 35ppm,   250L community (bigger fish) 25ppm down to 15ppm, the 350L 20-ish cichi tank 40ppm down to 25ppm.. conclusion, I'm gonna keep chkn nitrates in the tanks using the Tetra kit. I was also told that API kit will rarely give a clean zero for ammonia, again my experience - it's always sorta 0.1..but I'll take that.. and lookin' to get individual 'single-chemo' kits in the future. My  reduction in water bill will easily pay for the new kits, lol..  ;D
Ok, separate from Sue's statement about different standards between UK and US, SEACHEM claims that the API test kit test for TOTAL ammonia.  They say if you use their product PRIME, that it binds a portion of the ammonia rendering it non-toxic (for about 48 hours).  So, after using PRIME, the API test kit will still show an elevated ammonia level, but most of it has been bound by PRIME and is not "free".  I take it that this may be self-serving, because SEACHEM's next recommendation is to buy THEIR test kit, which only measures "free" (toxic) ammonia and is therefore more accurate.  Or by using their little "Ammonia Alert" badges, which hang inside the glass of the tank.  I am a little cynical about the claims of all these vendors, and I would take with some caution your local fish salesman that happens to have become convinced the Tetra product is better.  In the US, Tetra sells "test strips" and they many people have found them to be inaccurate and not consistent with other measures.  If I had to put my money on any of these companies with regard to their product reliability, I would be more likely to trust SEACHEM than TETRA.  Just my humble opinion
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Matt on August 26, 2019, 06:10:38 AM
Probably not fair to compare the two products in this way. Tetras product is there for convenience and seachems for accuracy. Seachems also refuse to tell us what's in their PRIME dechlorinator... not that I have any affiliation with either brand.

You might also be interested to read this forum thread where we have covered this topic before (credit to Sue).

https://forums.thinkfish.co.uk/general-fishkeeping-advice/acceptable-ammonia-level/ (https://forums.thinkfish.co.uk/general-fishkeeping-advice/acceptable-ammonia-level/)

There is more free ammonia at a higher pH.

http://www.aquaworldaquarium.com/Articles/TonyGriffitts/Ammonia.htm (http://www.aquaworldaquarium.com/Articles/TonyGriffitts/Ammonia.htm)
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Sue on August 26, 2019, 10:51:11 AM
I didn't make myself very clear, sorry.

The home nitrate testers are the same the world over. They test nitrate-NO3.

The thing which differs is water testing companies nitrate results. I wasn't sure if you were saying that 50 ppm allowed in drinking water in the UK was the reason that so many regions of the UK have 40+ ppm - that water companies don't have to try hard to get it lower. But that in the US, the legal limit is something like 10 ppm so US water companies have to make sure they get it down below that.
I just wanted to say that the US upper limit is virtually the same as the UK upper limit; they just appear different because of the way they measure it. So the reason that a lot UK nitrate levels are high is for some other reason.



As for ammonia, our liquid reagent test kits read total ammonia - ammonia and ammonium combined. And when a dechlorinator of any brand which 'detoxifies' ammonia is used, the 'detoxified' ammonia also registers in the test.
Most, if not all, of the liquid reagent home testers use the salicylate reaction. The FAQs on Seacem's website for Prime state
Quote
A salicylate based kit can be used, but with caution. Under the conditions of a salicylate kit the ammonia-Prime® complex will be broken down eventually giving a false reading of ammonia (same as with other products like Prime®), so the key with a salicylate kit is to take the reading right away.
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: dwindstr on August 26, 2019, 05:06:25 PM
There is more free ammonia at a higher pH.

http://www.aquaworldaquarium.com/Articles/TonyGriffitts/Ammonia.htm (http://www.aquaworldaquarium.com/Articles/TonyGriffitts/Ammonia.htm)
Thanks for that article with the details about relationship to ph.  Since I keep my water at 7.0 or below, it appears I have less to worry about than I realized.  It would be interesting to actually test the accuracy of Seachem's test kit, which purports to separate out the measurement of free ammonia.  In my case, according to the article, it appears that the API Test is not going to be that helpful unless I had a really significant problem.
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Sue on August 26, 2019, 09:13:00 PM
If you use the API test in conjunction with a free ammonia calculator such as https://www.hamzasreef.com/Contents/Calculators/FreeAmmonia.php it will give you a better understanding of your ammonia level. The aim is to keep free ammonia below 0.02 ppm.
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: dwindstr on August 27, 2019, 07:05:36 PM
If you use the API test in conjunction with a free ammonia calculator such as https://www.hamzasreef.com/Contents/Calculators/FreeAmmonia.php it will give you a better understanding of your ammonia level. The aim is to keep free ammonia below 0.02 ppm.
I am assuming this estimate cannot take into account the amount of additional "free ammonia" that has been bound as a result of using Seachem's PRIME; in which case the amount of free ammonia would be even lower. 

One other question: how do I derive the measure of "salinity" in this calculator.  I have a freshwater tank.  Could I use the results from the API GH or KH test kit?
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Sue on August 27, 2019, 07:09:50 PM
In a freshwater tank the salinity is zero. The calculator is for both freshwater and marine so that parameter has to be included for marine tanks.
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: daveyng on September 18, 2019, 10:58:47 AM
When I first went down the tap/RO water change route. I created a simple graph based on a 50/50 mix of tap/RO water.
This gave me an idea of the number of days required to push the Nitrate level down from 40 ppm to 20 ppm.
This is based on daily water changes and uses a reduction based on the static volume of the tank and the percentage of water changed.
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: jaypeecee on September 18, 2019, 01:38:15 PM
When I first went down the tap/RO water change route. I created a simple graph based on a 50/50 mix of tap/RO water.
This gave me an idea of the number of days required to push the Nitrate level down from 40 ppm to 20 ppm.
This is based on daily water changes and uses a reduction based on the static volume of the tank and the percentage of water changed.

Hi daveyng,

What is the nitrate level in your tap water?

JPC
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: daveyng on September 18, 2019, 01:45:19 PM
@jaypeecee the nitrate level is quoted at a max of 38 ppm.
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: daveyng on September 18, 2019, 04:58:18 PM
Just to continue from my last message. The Nitrate Levels for my area range from 30 ppm - 38 ppm (average 34 ppm). I chose the figure of 40 ppm arbitrarily as it encompassed the worst case scenario.

Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: jaypeecee on September 18, 2019, 06:49:23 PM
Hi,

If you do progressive water changes with a 50/50 mix of tap/RO water, then the GH and KH will also be reduced accordingly, won't they? If so, that may not be advisable. Other parameters would also follow the same pattern. In an unplanted tank, I would prefer to use an ion exchange resin to remove nitrate such as JBL NitratEx. In a planted tank, the plants will absorb the nitrate.

JPC
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: daveyng on September 18, 2019, 10:29:29 PM
Hi @jaypeecee I actually did the 50/50 tap/RO mix to reduce the GH and KH of the tap water. It’s moderately hard so even at 50% dilution has buffering capacity. I have some species of fish from soft water areas so this benefits them.
I have attached the water quality summary for information in PDF format.

Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: daveyng on September 18, 2019, 10:46:28 PM
I think the attachment failed. This is the second attempt.
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Hampalong on September 19, 2019, 10:09:20 AM
A quick note on ammonia. Just to clarify (if it isn’t clear) a dechlorinator that detoxifies free ammonia simply converts it into ammonium, temporarily.
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: Sue on September 19, 2019, 04:50:52 PM
With temporary being around 24 hours.



In regions where the water company uses chloramine to disinfect the mains water, ammonia is left after the dechlorinator removed the chlorine part. The ammonia detoxifier converts this ammonia to ammonium for around 24 hours by which time the 'filter' bacteria should have removed it.
Title: Re: What is a safe maximum nitrate level for freshwater fish?
Post by: jaypeecee on September 20, 2019, 06:40:48 PM
Hi @jaypeecee I actually did the 50/50 tap/RO mix to reduce the GH and KH of the tap water. It’s moderately hard so even at 50% dilution has buffering capacity. I have some species of fish from soft water areas so this benefits them.
I have attached the water quality summary for information in PDF format.

Hi daveyng,

Thanks. Now I can see why you did the 50/50 water changes. Not to reduce nitrate but to reduce GH and KH. Like yourself, I have soft water fish - notably German Blue Rams (GBRs) and others. I use re-mineralized RO water. Thanks also for the water report. It's always interesting to compare with my own tap water - even though I don't use it for fishkeeping!

JPC