See less of these, support the forums and become a Super Subscriber today!

We also have sponsorship opportunities for tropical fish related businesses from just 20 per month.

Restocking A Slightly Acidic, Softer Water Planted Tank

Author Topic: Restocking a slightly acidic, softer water planted tank  (Read 7613 times)

0 Members and 1 Guest are viewing this topic.

Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #50 on: November 25, 2017, 02:25:19 PM »
  • Likes On This Users Post 0
It's difficult to tell, but I think the trend continues. It doesn't help that I had a few days after the slide ran out before I put the new one in.

Edit: I should have said that the trace below shows the last week's readings.

Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #51 on: November 25, 2017, 02:31:11 PM »
  • Likes On This Users Post 0
The pH seems to almost directly follows the lighting pattern. The first peak is about lunchtime, just before the lights go out for the siesta. And the tank is in the lounge, so the evening peak is higher because we usually have the lounge lights on (additional background lighting)

Offline Sue

  • Global Moderator
  • Hero Think Fishy Member
  • *****
  • Posts: 7893
  • Likes: 169
Re: Restocking a slightly acidic, softer water planted tank
« Reply #52 on: November 25, 2017, 02:37:02 PM »
  • Likes On This Users Post 0
That is what I would expect in a planted tank. The pH drops to its lowest just before light reaches the tank. It increases when the tank lights come on for their first period, then drops as they enter the off period, but not as low as during the night.. When the lights come on for the second time, the pH rises again. Once the tank and room lights go out, the pH drops to its lowest point just before it gets light again next day.
When the tank lights are on, the plants take up CO2 so the pH rises; when all the lights are off, plants do not take up CO2 so the CO2 level in the tank increases and the pH falls.

The only mysterious thing is the very slight increase day on day.

Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #53 on: November 25, 2017, 02:47:59 PM »
  • Likes On This Users Post 0
The only thing I can think of is that my tank is no more than 20% stocked with fish at the moment. And that the consumption of CO2 during lit hours exceeds it's generation during lights off.

If that is the case, the trend should change as I increase my stock.

Offline Littlefish

  • Global Moderator Subscriber
  • Hero Think Fishy Member
  • *****
  • Posts: 2568
  • Likes: 153
  • aka Donna
Re: Restocking a slightly acidic, softer water planted tank
« Reply #54 on: November 25, 2017, 02:49:57 PM »
  • Likes On This Users Post 0
Thanks @Matt for linking to the thread where I was having problems with my pH. It saves me finding it.  :)

@Helen it will be interesting to see if the readings stabilise as you stock your tank further.


Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #55 on: January 12, 2018, 11:29:55 PM »
  • Likes On This Users Post 0
So I'd like to start buying new fish this weekend.  :fishy1:

But I'm a bit worried about the pH of my tank. It is supposed to be neutral to slightly acidic (and all the fish I have chosen are suitable for this), but it is currently 8.1 - 8.2.

I plan to do all the water tests that I have tomorrow (Nitrate, P, K, GH, KH, 6 in 1 test strip that includes pH, nitrate and both hardness).

I suspect that the high pH is due to lack of CO2 (and Kh buffering), because the pH variation with lighting has more or less disappeared. But how do I check this? I have a CO2 kit, but I've not used it for at least a couple years, so I'm not sure how to check it works (properly) and am slightly worried about causing a pH crash if my Kh turns out to be low (which I suspect, but can confirm tomorrow).

I will post test results, and then ask for suggestions, I guess.

Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #56 on: January 13, 2018, 01:11:43 PM »
  • Likes On This Users Post 0
So some test results:

Tank water
pH 7.0 - 7.5
Nitrate 10 (a little higher, but no where near as high as 25, which is the next colour on the chart)
GH 107ppm
KH 72ppm
Phosphate 1mg/l
Potassium 20mg

Rested de-chlorinated water
GH 54ppm
KH 36-54ppm

The fact that the 3 macro nutrients are as high as they are, suggests to me that my plants aren't growing. So something else is the limiting factor. This supports my theory of low CO2.

What is interesting to me is that the hardness in the tank is higher than that of my tap water. I do have a lot of small snail shells in the tank, could these be the source, or do I need to test my rocks?

Offline Sue

  • Global Moderator
  • Hero Think Fishy Member
  • *****
  • Posts: 7893
  • Likes: 169
Re: Restocking a slightly acidic, softer water planted tank
« Reply #57 on: January 13, 2018, 01:44:43 PM »
  • Likes On This Users Post 0
It could be the snail shells but I would still test the rocks. It is worth knowing everything there is to know about tank decor  :)

Offline Littlefish

  • Global Moderator Subscriber
  • Hero Think Fishy Member
  • *****
  • Posts: 2568
  • Likes: 153
  • aka Donna
Re: Restocking a slightly acidic, softer water planted tank
« Reply #58 on: January 13, 2018, 01:49:07 PM »
  • Likes On This Users Post 0
I agree with Sue.
Fluctuations in mineral content could have a negative impact on your fish if you end up performing larger/less frequent water changes.
Best to investigate & resolve now before you put anything else in the tank.

Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #59 on: January 13, 2018, 01:57:23 PM »
  • Likes On This Users Post 0
Do I test the rocks by dripping kitchen vinegar on them? Or some other way?

Offline Littlefish

  • Global Moderator Subscriber
  • Hero Think Fishy Member
  • *****
  • Posts: 2568
  • Likes: 153
  • aka Donna
Re: Restocking a slightly acidic, softer water planted tank
« Reply #60 on: January 13, 2018, 02:17:41 PM »
  • Likes On This Users Post 0
The vinegar test is what I've done before.

Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #61 on: January 13, 2018, 05:12:20 PM »
  • Likes On This Users Post 0
No fizzing at all from the vinegar test.

I got my CO2 diffuser out - it's going to need some significant scrubbing!  :-[

Offline Littlefish

  • Global Moderator Subscriber
  • Hero Think Fishy Member
  • *****
  • Posts: 2568
  • Likes: 153
  • aka Donna
Re: Restocking a slightly acidic, softer water planted tank
« Reply #62 on: January 13, 2018, 05:54:30 PM »
  • Likes On This Users Post 0
What else is in your tank?

Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #63 on: January 13, 2018, 07:03:24 PM »
  • Likes On This Users Post 0
I have lots of wood (that has been in my tank from the beginning). The substrate is Eco complete and small gravel. And I have lots of plants.

I do have several years accumulation of snail shells. I think my kuhlis eat the snails so I very rarely have snail problems.

Offline Matt

  • Global Moderator
  • Hero Think Fishy Member
  • *****
  • Posts: 1168
  • Likes: 93
Re: Restocking a slightly acidic, softer water planted tank
« Reply #64 on: January 13, 2018, 07:34:40 PM »
  • Likes On This Users Post 0
It would be interesting to see how quickly the hardness increases following a water change...

Are you adding any chemicals to the tank other than dechlorinator?

Offline Littlefish

  • Global Moderator Subscriber
  • Hero Think Fishy Member
  • *****
  • Posts: 2568
  • Likes: 153
  • aka Donna
Re: Restocking a slightly acidic, softer water planted tank
« Reply #65 on: January 13, 2018, 09:57:49 PM »
  • Likes On This Users Post 0
Do you top up evaporated water from you tank, or only ever do water changes?
I'm wondering if you are having some evaporation issues, which may cause problems.

Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #66 on: January 13, 2018, 10:24:37 PM »
  • Likes On This Users Post 0
I'm not adding any fertilisers at the moment. I wanted the tank to settle after all the rearranging so that I could get a baseline from which to work out the correct amounts of any required supplements.

During the period of neglect I topped up evaporation once (about 5l in 170l).

The amount of water in my tank has increased from 170l (measured at initial setup) to 220l (estimated) with all the substrate removal. Does that count?

I am contemplating doing a couple large water changes tomorrow to see if that makes a difference. Think I've run out of time this evening.

Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #67 on: January 13, 2018, 10:33:15 PM »
  • Likes On This Users Post 0
It's just occurred to me that I could have an evaporation issue and not necessarily know about it. My tank has a footprint of 120cm X 45cm, so I could lose a litre and not necessarily notice unless it was at exactly the right level at the top of the tank that a couple mm change in depth showed.

So what can I do about it? A regular large (>50%) water change?

Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #68 on: January 13, 2018, 10:35:57 PM »
  • Likes On This Users Post 0
If I do go down the route of large water changes, are there any limits so I don't cause my existing fish distress?

Should I do a larger than normal water change before getting at new fish?

Offline Littlefish

  • Global Moderator Subscriber
  • Hero Think Fishy Member
  • *****
  • Posts: 2568
  • Likes: 153
  • aka Donna
Re: Restocking a slightly acidic, softer water planted tank
« Reply #69 on: January 13, 2018, 10:52:03 PM »
  • Likes On This Users Post 0
I only mentioned evaporation because it's a problem I have on my betta tank (which doesn't have a lid). I top up with RO in between water changes.
Pure water evaporates and leaves the minerals, so topping up with tap water would increase hardness over a period of time.
I'm just throwing ideas out there and I'm certain that the quantities that you are talking about wouldn't cause problems.

Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #70 on: January 13, 2018, 10:54:46 PM »
  • Likes On This Users Post 0
I've just wondered if perhaps it is less of a problem than I initially thought.

My hardness in my tank is 107ppm (moderately soft), in comparison with the hardness of my tap water at 54ppm (soft). Both are easily within the preferred range of all my current fish.

It is the pH that might be an issue, but I keep coming back to lack of CO2, as I have no better ideas.

Do I have enough buffering (Kh = 72ppm) to avoid a potential pH crash if I add CO2?

If my tap water is softer than my tank water, would there be much benefit in using RO to top up?

Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #71 on: January 13, 2018, 11:07:07 PM »
  • Likes On This Users Post 0
Looking again at water quality in so much detail has got me thinking about my potential stock list again. There are a couple potential clashes that I'd like other opinions on.

Kuhli loaches and BN Plec with a pair of kribensis.
Kuhlis and the BN Plec get on ok as they've got their own favourite spaces (Bertie claims the caves, the kuhlis like the bogwood/ crypts). If I increase the number of kuhlis and introduce a pair of Kribensis, am I risking a clash over caves? What's the minimum number of new cave areas that i would need to introduce to avoid conflict? Should I limit the number of kuhlis I increase to? (Currently proposed to be 14)

According to Seriously Fish, 5 band barbs have a max hardness of 90ppm and Dwarf Rainbow fish have a minimum hardness of 90ppm. Although my hardness seems to be around this, in reality it isn't ever going to be spot on 90ppm. Do I need to find alternative choices? (Neither of these species are in my tank yet)

Offline Littlefish

  • Global Moderator Subscriber
  • Hero Think Fishy Member
  • *****
  • Posts: 2568
  • Likes: 153
  • aka Donna
Re: Restocking a slightly acidic, softer water planted tank
« Reply #72 on: January 13, 2018, 11:07:56 PM »
  • Likes On This Users Post 0
Are you testing your tap water straight after taking it from the tap?
The pH of my tap water changes over a 3 day period. It is 7.0 - 7.2 straight from tap, then increases to around 8.2 over around 3 days. This will also be reflected in your tank, as it is in mine.
I have quite hard water, so don't know what sort of impact the changes would have on your tank. To avoid large(ish) fluctuations in your water parameters smaller/more frequent water changes would be better.

Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #73 on: January 13, 2018, 11:11:54 PM »
  • Likes On This Users Post 0
I had a couple litres of de-chlorinated water left over from my last water change (last week). So I used this as the tap water sample. Could that have skewed the result? (I remembered you saying before about the significant change in the pH of your tap and tank water @Littlefish )

Offline Littlefish

  • Global Moderator Subscriber
  • Hero Think Fishy Member
  • *****
  • Posts: 2568
  • Likes: 153
  • aka Donna
Re: Restocking a slightly acidic, softer water planted tank
« Reply #74 on: January 13, 2018, 11:17:55 PM »
  • Likes On This Users Post 0
There are also discussions to be had regarding the parameters listed for specific fish, and whether they were wild caught or commercially bred (in different water conditions), etc.
Unfortunately it can be a complex discussion, and I've had a couple of glasses of wine tonight, so I may have to pick this one up again tomorrow.

Just saw your other post.
My previous discussions with Sue and others concluded with us thinking that perhaps the water company added CO2 a source to ensure that pH was neutral at the tap. The would gas off over a couple of days, revealing the true pH of the water. I would have expected that dechlorinated water from the previous week would have shown the "true" pH, which may still be lower than your tank pH.

Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #75 on: January 13, 2018, 11:37:39 PM »
  • Likes On This Users Post 0
Thanks @Littlefish .

Surely after wine is the best time to have deep conversations?  :cheers:

Argh. I so want to buy more fish, but don't want to endanger them if my tank isn't ready.  :fishy1: :vcross:

Offline Matt

  • Global Moderator
  • Hero Think Fishy Member
  • *****
  • Posts: 1168
  • Likes: 93
Re: Restocking a slightly acidic, softer water planted tank
« Reply #76 on: January 14, 2018, 06:50:59 AM »
  • Likes On This Users Post 0
I would suggest you do a large water change @Helen (and in answer to your previous question this means no more than 50%) then give the tank a few days to settle and see what your test results are. If they have changed since your previous results, give it another week and test again.  Again, see how they have changed. We want to get to a point where we understand a) what's causing the hardness to increase in your tank, and b) what the stable hardness level is likely to be once things settle down in the tank.  The above plan should give us a good feel for both.  :cheers:

Offline Littlefish

  • Global Moderator Subscriber
  • Hero Think Fishy Member
  • *****
  • Posts: 2568
  • Likes: 153
  • aka Donna
Re: Restocking a slightly acidic, softer water planted tank
« Reply #77 on: January 14, 2018, 01:01:41 PM »
  • Likes On This Users Post 0
You are doing the right thing by ensuring you have your tank right before getting your fish.
Patience isn't my strong point, and I was very frustrated when I was in a similar situation.
Hopefully another week won't be too long.  :)

Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #78 on: January 14, 2018, 02:04:11 PM »
  • Likes On This Users Post 0
I changed 105l this morning.  :yikes:
I can't see me ever changing more than 50% of the tank water unless under dire emergency. It was quite hard work.

While I was doing it, I got to thinking about all our recent discussions. Over the Christmas break, we've had a lot of children in the house. My kids know not to touch my fish tank, but I realised that young children seem rather fascinated with the magnets that hold my Seneye in place. And so it gradually moved up the tank, as far as I could get it. I have now moved it back to what I think is the most sensible location - in the middle (horizontally and vertically) of the short side of the tank (furthest from the filter).

I know position in the tank will affect the temperature readings, but does it affect any of the other readings? Also the water samples I did the tests on came from the top few cms of the tank water.

And then I got to thinking about what you had said @Littlefish  about the water companies adding CO2 to reduce pH to neutral. If my problem is lack of CO2, then any additional CO2 can only be good for my tank. But also, if I am concerned about pH swings from large water changes, then I really need to know the pH of the water when it goes into my tank (rather than when it has had time to off gas).

Offline Littlefish

  • Global Moderator Subscriber
  • Hero Think Fishy Member
  • *****
  • Posts: 2568
  • Likes: 153
  • aka Donna
Re: Restocking a slightly acidic, softer water planted tank
« Reply #79 on: January 14, 2018, 03:00:24 PM »
  • Likes On This Users Post 0
Large water changes are hard work.

I'm fairly certain that quite some time ago someone posted about location of water samples, and said that they took samples from deeper in the tank. Perhaps @Sue will remember this (I think it was posted by ExremeOne/Simon, perhaps I'll be able to find it).

I also remember someone mentioning that they ran off several containers of water a few days prior to their water changes, to allow time to gassing off and reaching room temperature, but I can;t remember if that was here or at a shop. Sorry I'm being a bit vague today, I'm blaming it in the wine last night.  :)

Offline Sue

  • Global Moderator
  • Hero Think Fishy Member
  • *****
  • Posts: 7893
  • Likes: 169
Re: Restocking a slightly acidic, softer water planted tank
« Reply #80 on: January 14, 2018, 03:45:01 PM »
  • Likes On This Users Post 0
Leaving water to stand for days is one way of gassing off chlorine, but that doesn't work if the water company uses chloramine.

In hard water areas, water companies often add something, usually CO2, to reduce the pH and help prevent limescale build up in the mains pipes. In places with very soft acidic water, they add some thing to raise the pH to prevent corrosion of metal pipes. Both of these gas off, and the pH reverts to its untreated level. So leaving water standing for at least a day will avoid pH swings after a water change.
But there are other considerations - do you have a childproof place to leave 105 litres water to degas? And if you do, how easy would it be to transport the water from this place to your tank?


But this only affects pH and not hardness. The only way hardness increases is by adding calcium and/or magnesium to the water (hardness being a measure of calcium and magnesium) If your tank hardness is higher than your tap hardness, something in the tank is adding calcium and/or magnesium. This could be topping up with tap water between water changes, calcareous decor dissolving, or something in your new substrate.
The vinegar test is not 100% reliable. The better, but more time consuming, way is to put each piece of decor into a small container of water. Test the hardness as soon as it is put in the container, and again after 1 week. And swirl the water up before taking the sample to make sure it is thoroughly mixed up. If there is any substrate left over, test that as well.

It is also worth doing some pH testing. Run a large glassful of water and test it immediately. Then again after 1 day, 1 week, and as many times during that week as you feel like doing. And test the decor-containing water after a week as well as the hardness.

If we can pin down what is causing the tank levels, we can work out a way of coping with it.

Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #81 on: January 14, 2018, 10:31:46 PM »
  • Likes On This Users Post 0
I definitely don't have the ability to store more than 10l of new water. It pretty much comes out of the tap and goes into the tank. 10l at a time, dechlorinator added as the "in" bucket fills up. I lug "in" bucket halfway across the house, up in my step and slowly pour it into the tank so as not to disturb the substrate.

The only new substrate is the play sand, which was washed till the water was clear with removed tank water (in the "out" bucket). The increase in pH trend started before the sand went in and didn't seem to be affected by it. But I did wash too much sand and have kept hold of the excess.

The fine gravel substrate came out of the tank, was sieved and then went back in.

I think I might have to buy another pH test kit. At the moment I have my Seneye and a 6 in 1 test strip (which I think is pretty awful!). So I'm struggling to get a reliable reading on my tap water.

In the past I have added calcium to the tank in the form of calcium nitrate. But not for many months and I have changed a lot of water since then.

How accurate are the hardness tests? I ask because the difference between the two readings is 3 drops of reagent for GH and 1-2 drops for KH.

And lastly, I have to say thank you for all your support that I was doing the right think micro analysing my water parameters. But I caved. This afternoon a dozen five band barbs joined my tank.  :-[  :fishy1: They are a similar size to my harlies at the moment, so I think they are a total of about 36cm.

Offline Littlefish

  • Global Moderator Subscriber
  • Hero Think Fishy Member
  • *****
  • Posts: 2568
  • Likes: 153
  • aka Donna
Re: Restocking a slightly acidic, softer water planted tank
« Reply #82 on: January 14, 2018, 11:01:28 PM »
  • Likes On This Users Post 0
From my own experience I can safely say that I nearly disappeared up my own bottom trying to work out whar was going on with my water. I spent days testing glasses if tap water over several days, checking what decor/hardscape materials I had in my tanks, and drawing lines on post-its (other brands of sticky note are available) to monitor water evaporation.
Seriously, you can drive yourself nuts over this.

Nice choice of fish, pics required when they are settled.  :)

Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #83 on: January 14, 2018, 11:09:17 PM »
  • Likes On This Users Post 0
Thank you @Littlefish  :cheers:

Offline Matt

  • Global Moderator
  • Hero Think Fishy Member
  • *****
  • Posts: 1168
  • Likes: 93
Re: Restocking a slightly acidic, softer water planted tank
« Reply #84 on: January 15, 2018, 07:00:39 AM »
  • Likes On This Users Post 0
I like fivebands but Mrs Matt doesn't... so I have fish jealousy right now!!

Pictures should really be put in the forum rules  :cheers:

Offline Littlefish

  • Global Moderator Subscriber
  • Hero Think Fishy Member
  • *****
  • Posts: 2568
  • Likes: 153
  • aka Donna
Re: Restocking a slightly acidic, softer water planted tank
« Reply #85 on: January 15, 2018, 10:00:28 AM »
  • Likes On This Users Post 0

Pictures should really be put in the forum rules  :cheers:

 :rotfl:

Offline Sue

  • Global Moderator
  • Hero Think Fishy Member
  • *****
  • Posts: 7893
  • Likes: 169
Re: Restocking a slightly acidic, softer water planted tank
« Reply #86 on: January 15, 2018, 10:16:51 AM »
  • Likes On This Users Post 0
To be honest, as long as your tank water is stable - the GH is not constantly increasing - I wouldn't worry too much.

I use buckets to refill my tank, though because of the dose rate of the dechlorinator it is 9.5 litres per bucket. But i don't pour it in from the bucket, I put that on a stool and ladle the water with a jug and through a home made colander which stops the water stream from making a hole in the sand. The colander is a 170g, Total yogurt pot with as many holes in the bottom as I could make with a knitting needle without them merging into one big hole. Using this will also aerate the new water slightly, driving out any of these temporary pH alterers (not much but a bit)

Hmmm, that calls for a test to see just how much effect next time I do a water change ......

Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #87 on: January 22, 2018, 01:46:43 PM »
  • Likes On This Users Post 0
I've just ordered / reserved some kuhli loaches from my local MA. What are thoughts on 14 kuhli loaches with a pair of kribs in my 240l planted tank? I intend to include some more caves in the tank, but my main concern is that if 14 kuhlis is a good number for the tank, is it too many with the kribs?

Would that many substrate "hunters" be too stressful for a breeding pair of Kribensis?

Offline Matt

  • Global Moderator
  • Hero Think Fishy Member
  • *****
  • Posts: 1168
  • Likes: 93
Re: Restocking a slightly acidic, softer water planted tank
« Reply #88 on: January 22, 2018, 08:30:24 PM »
  • Likes On This Users Post 0
14 khuli loaches is rather a lot, not necessarily a problem provided you have the right foods to feed them. It would very likely become a problem if the kribs bred though as they would aggressively defend the eggs and I'm not sure khuli loaches would understand this territorality - I know corys definitely don't and will just keep trying until they get beaten up.

Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #89 on: January 22, 2018, 10:42:31 PM »
  • Likes On This Users Post 0
That is exactly what I am worried about @Matt. The kuhlis are staying on the shopping list, it is just whether I could alleviate the problem by having fewer kuhlis. If so, how many?

Or do I need to take kribs off my shopping list? They would be the last fish to go in the tank, so are a way off.

How much could I influence the kribs territory? Would a strategically placed cave help, or would they be more likely just to pick a different one? That said, my two current kuhlis seem to be enjoying the whole of the tank. The refurb seems to have made it all more to their liking.

The other issue, that has me thinking twice about getting even the kuhlis this weekend is that the pH in my tank is still going down. The maximum readings over the last week have been (all at 10pm):
(Barbs introduced Sunday afternoon)
Monday: 8.06
Tuesday: 8.16
Wednesday: 8.03
Thursday: 8.03
Friday: 7.96
Saturday: 7.92
Sunday: 7.92
Monday (today): 7.76

At which point do I start to worry and what can I do about it? The pH of my tap water is approximately the same as the tank pH today.

Offline Matt

  • Global Moderator
  • Hero Think Fishy Member
  • *****
  • Posts: 1168
  • Likes: 93
Re: Restocking a slightly acidic, softer water planted tank
« Reply #90 on: January 23, 2018, 07:15:46 AM »
  • Likes On This Users Post 0
OK so a couple of things occurred to me this morning about the pH drop you are experiencing... @Sue will need to check my understanding of all this because chemistry is not my strong suit!

Filter bacteria need carbonates to grow. The amount of carbonates are measured through measuring water hardness. So as filter bacteria grow they reduce water hardness. Water hardness is partly responsible for stabilising pH (this is the bit I don't understand but I know to be true). Further to this as filter bacteria do their thing they produce hydrogen ions (again why... I don't know) this lowers the pH of the water (pH I believe is a measure of hydrogen ions). So a double whammy on reducing pH

You have added fish recently so I'm assuming more filter bacteria are growing and depleting the water carbonates and hardness.  There are more filter bacteria producing hydrogen ions and all this  is acting to lower the pH.  Now I would assume that if all of this is true them you would see a drop in the hardness levels in your tank... have you?

I would also assume that a water change would be the way to raise the hardness... is you tap water harder than your tank water?

I also know that @fcmf  has a small piece of tufa rock I think it is in her filter to increase hardness and buffer pH which could be a longer term solution.

Phew... does any of that ring true @Helen ?

Back to khulis and kribs... strategic caves is a good shout, though if the khulis go everywhere that may not help... I wonder could the cave be elevated in some way to detract the khulis but not the kribs? I don't know why I'm going to say 6-8 khulis sounds right but I am, it's an opinion based in no logic!!

Oh dear I'm not sure I'm helping much   :-[

Offline Sue

  • Global Moderator
  • Hero Think Fishy Member
  • *****
  • Posts: 7893
  • Likes: 169
Re: Restocking a slightly acidic, softer water planted tank
« Reply #91 on: January 23, 2018, 11:18:23 AM »
  • Likes On This Users Post 0
Carbonates are measured by KH. I don't think the bacteria themselves have much impact on the amount of carbonates, though they may use more when increasing the numbers of them; when they are just keeping the population stable (some dying, new ones replacing them) there should be little impact.

In a cycled tank, there are undetectable levels of ammonia and nitrite but nitrate is constantly being made. This is acidic - unless something stops it, it lowers the pH. Other chemicals produced by fish, plants, micro-organisms of all sorts are also acidic. These chemicals are waste products, hormones and so on - remember that fish communicate with each other by chemical signals.

When acids, bases and salts dissolve in water they dissociate into ions.

Carbonate is CO32- , carbonic acid is H2CO3 It dissociates like this:
H2CO3 -> 2H+ + CO32-

and it can also lose just 1 hydrogen ion to make bicarbonate
H2CO3 -> H+ + HCO3-


The reactions above are reversible; they go backwards as well. In fact they are continually going backwards and forwards but there are always the same number as H2CO3 and as ions.
However, if something happens to disrupt the balance, things change. Add more H+ to the right hand side and it pushes the reaction over to the left. So when hydrogen ions are made by nitrate production and all those chemicals secreted by things in the tank it converts more carbonate ions into carbonic acid molecules. This reaction removes the free hydrogen ions from the water so the amount of them stays constant and the pH stays constant.

With low KH there isn't much carbonate so all of it ends up being converted quite quickly. Once it is all converted to H2CO3, there is nothing left to remove hydrogen ions so they build up and the pH falls.
When the KH is high, there is so much that it would take months for it all to be converted. And the fish would suffer from Old Tank Syndrome well before all the carbonate had been used.

Water changes remove H2CO3 and put more carbonate in the water. Even with very low KH, regular large water changes are enough to stop the pH falling.




EDIT TO ADD

When carbon dioxide builds up in the water it forms more carbonic acid. This pushed the equation from left to right, which means there are more hydrogen ions so the pH drops.

Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #92 on: January 23, 2018, 12:50:17 PM »
  • Likes On This Users Post 0
Thank you @Sue and @Matt for your comprehensive responses.

A few quick replies.
6-8 kuhlis works well with me. So that is what I will go for this weekend. I can always get more instead of kribs if my plans change following further research. I will add extra caves later, so there's no issue with territories being marked before all fish are in.

Water conditions in my tank at the moment (based on yesterday's readings) are pretty much the same as my tap water. (Except for pH, this has been more or less the case since I changed 105l on Sunday morning before adding fish) 
Nitrate about 5ppm.
GH 5 drops
KH 2-3 drops
Max pH has dropped from 8.16 to 7.76

It could just be that the addition of fish is causing my tank to stabilise and is undoing the still unexplained increase in pH.

I will keep monitoring and do a large water change if the pH looks like it isn't stabilising. If that solves the problem, I will start to consider additives.

Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #93 on: January 27, 2018, 12:55:30 PM »
  • Likes On This Users Post 0
So the water conditions started to stabilise. I still have the daily variation in pH, but it is back to reflecting the lighting regime. Ie pH at its highest at 10pm, when the lights go off, and at minimum at 7am just before the lights come on, with a noticeable dip during siesta time.

I did a 40l water change last night and changed the slide in my Seneye. With hindsight, I shouldn't have done these at the same time. There was a slight jump in pH, which I think was due to the slide change. I don't think it would be noticeable with a standard / liquid test, because it's either side of a colour reading. (Ie, both readings would look like 7.8 )

So off to the fish shop I went this morning. Sadly the kuhlis that I was going to get didn't survive the lfs quarantine. 🙁 So no more kuhlis. So I decided instead to get the next fish on my list - neon dwarf rainbow fish. 9 little beauties are currently acclimatising. Hopefully I've got 5 female and 4 males. In the shop tank it was easy to see the difference between the red and yellow fins. But not once they were being caught and put in the bag. So I guess I'll have to wait till the tank lights come back on to check. In the dark tank , they already look like they're starting to colour up, but I'm not sure that's just a trick of the light.
 :fishy1: :fishy1:




Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #94 on: February 01, 2018, 10:29:16 PM »
  • Likes On This Users Post 0
So the pH seems to have taken about 3 days to settle back to where it was pre slide change and fish introduction. I'm not entirely sure which caused which affect, but I suspect that the slide change had the more significant effect (that had 12-15 hours to do it's thing before the additional fish joined the party)

I am really impressed with how quickly the rainbows are colouring up. They're only about 3cm, so I was expecting them to have to grow quite a bit more before I got the gorgeous colours in the photo on the profile. Clearly not there yet, but they are sufficiently coloured to hint at looking like their profile photo!

Need to do more hardness and macro nutrients tests at the weekend. I am also hoping to get a 10% water change in so I can monitor it's affect.

Offline Littlefish

  • Global Moderator Subscriber
  • Hero Think Fishy Member
  • *****
  • Posts: 2568
  • Likes: 153
  • aka Donna
Re: Restocking a slightly acidic, softer water planted tank
« Reply #95 on: February 02, 2018, 06:10:20 PM »
  • Likes On This Users Post 0
Great to hear that things are settling down and that your rainbows are settling in so quickly.  :)

Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #96 on: April 14, 2018, 09:05:02 AM »
  • Likes On This Users Post 0
So, current tank inhabitants:
6 harlequin rasbora
5 espeii rasbora
9 dwarf rainbow fish
12 fiveband barbs
2 kuhli loaches
1 BN Plec

Cc has me at 46% stocked.

I'd quite like to buy more fish. The plan had been to get more kuhlis at this stage, but I'm struggling with that a bit. I'm still interested in kribensis, but do want them to go in after the kuhlis.

So I'm looking at increasing the fish in the water column. Again the plan had been to double the number of rasboras, but I'm now wondering whether another, different coloured shoal would be more interesting. They need to be mid to surface swimmers and ideally no bigger than about 5cm.

I've had a quick look at emperor and penguin tetras, but am still researching their suitability. Any other ideas?

Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #97 on: April 14, 2018, 11:16:51 AM »
  • Likes On This Users Post 0
After a bit more research, I don't think emperor tetras would be suitable for my tank.

But I've had a look at sparkling gouramis. Any thoughts? @Matt I think I read that you've had them in the past?

In terms of space in my tank, I'd be able to add about a dozen fish that size. But I read they prefer smaller groups, so what would be an ideal number? Not totally sure they're the right fish, but at the moment they seem to 'tick all the boxes'.

Offline Matt

  • Global Moderator
  • Hero Think Fishy Member
  • *****
  • Posts: 1168
  • Likes: 93
Re: Restocking a slightly acidic, softer water planted tank
« Reply #98 on: April 14, 2018, 07:29:31 PM »
  • Likes On This Users Post 0
Gourami won't form a schoal, rather you will have largely individual fish which interact with the scape more than swim in the open... Im not sure from your original that they are quite what you are after...  have you looked at rummy nose tetras? They are similar colour with some great colour on the head and tail and one of the best schoalers you can get.

Offline Helen

  • Hero Think Fishy Member
  • *****
  • Posts: 527
  • Likes: 32
Re: Restocking a slightly acidic, softer water planted tank
« Reply #99 on: April 14, 2018, 08:00:43 PM »
  • Likes On This Users Post 0
Thanks @Matt . You're right, I do want a shoaling fish so sparkling gouramis won't be right. That's a shame, they looked nice fish. I think they'd get a bit lost in my tank though, if they don't shoal.

I have looked at several tetras - penguins, Black neons and x-rays. I'd not looked at rummy nose until you suggested it. I'm not sure rummy nose are the colour I'm after - I have a lot of red in my tank.  ;)

The thing that's making me hesitate about tetras is that they're all south American fish. The perfect fish would be an Asian one, as that's what my current shoaling fish are.

But I've not completely ruled out tetras yet.

See less of these, become a Super Subscriber today! We also have sponsorship opportunities for tropical fish related businesses from just 20 per month.

See less of these, become a Super Subscriber today (see below)

** Become a ThinkFish Super Subscriber **

It takes time and money to keep ThinkFish going, if you'd like to help, then a Subscription of your choice would be fantastic. Your subscription will help fund new articles, help pay for server costs and help fund development and promotion initiatives, helping us bring you more of the good stuff you love! You'll also see less ads. Why not become a Super Subscriber today!?

We also have sponsorship opportunities for tropical fish related businesses from just 20 per month.

Tags: restocking tank 
 

Sitemap 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 

Think Fish © 2004-2018 | Keeping Tropical Fish Forum - Everything you need for your Tropical Fish hobby

Tropical Fish Help and Advice
Tropical Fish Keeping Community
General Non-Fishkeeping Chat
Legal | Contact
SEO Services in Kent
Follow Think Fish on: