Water Hardness - Is Mine Within 'normal' Parameters?

Hi all,

i am currently fishless cycling a 78 litre tank which i hope to use for a small community tank of danios, tetras, possibly cherry barbs and hopefully some corys.

The water has been in the tank for a few days now and the tests are as follows:

GH - 180 or above definitely as dark blue as the strip goes.

KH - is 120

PH is 7

Do i need to have any concerns about the hardness or stability of my water?

Thanks

Yes, i have an API test kit, just using strips at this stage of the cycle.

I think i'm right in saying the higher the GH/KH the more stable the PH is so hopefully i won't have any major variations, but i will keep an eye.

Not really getting much readings on nitrites and nitrates yet. I'm using Kleen Off to introduce ammonia.

 Plus i have just added in some bog and driftwood which may alter PH. But that is the beauty of fishless cycling you can play around and all you lose is time.

Cheers

O.K I'm going right out on a limb here but am I right in thinking "water watcher's" ph is less likely to drop as her hardness is high? Is it just the carbonate hardness that helps stabilize the ph or the general hardness too?

I am interested in finding out and understanding more about aquarium water quality as I am close to getting my Discus. 

My readings are 0 for ammonia, nitrites and nitrates. My ph is a little high (7.6) but I'm going to do a large RO water change this week so that should help. The shop wrote down that my carbonate hardness was 17.9 but when I questioned this they said it only took 1 drop and that is absolutely fine.

I must get bottles to test carbonate and general hardness, I have ammonia, nitrite, nitrate and low and high ph. I'll also invest in a tds reader.

Can anyone recommend a book that explains all this in layman's terms?

Stuart.

Stuart,

As an afterthought, as it's now the following morning, I see you live in Bucks. So do I, near Aylesbury, so I would think that your tap water is very similar to mine.

My parameters are (after standing for 24hrs): pH 7.6; GH 16^o(296ppm); KH 12^o(215ppm)

It's a chalky (Calcium Carbonate) area around here so the Carbonate hardness will always be elevated, although it has to be less than the GH.

I really don't see how your LFS could test the KH to 17.9ppm or 1^o. If they also tested for Ammonia, Nitrite and Nitrate I'd be worried about the accuracy of those readings, too.

It's definitely worth getting the test kits and doing your own testing.

I use RO water to bring the hardness down to 12^o (which gives me a KH of 9^o) - but it has no effect on the pH because the water is so well buffered, so if you're intending to use the RO to bring the pH down to (say) 7 then it ain't gonna happen. You'll have to buy all RO water then 'build your own' water using the proper mix of 'salts' to get a low pH water that's well enough buffered not to suffer pH crashes. Either that or filter your water through peat. There're plenty of tutorials on the net on how to filter through peat - (though personally I would never use peat 'cos of environmental considerations).

These are just some thoughts that I think need thinking about before you get your fish. I'm really not trying to be negative in any way and I may have got the wrong end of the stick and you're totally sorted and prepared..... but I have a feeling that you're not there yet. (and I really wouldn't have spent 20mins typing all this out if I wasn't concerned - I'm still a two-fingered keyboard pecker )

So, is this right? The general hardness includes the carbonate hardness, but there are seperate tests to measure the carbonate hardness because ultimately it is the carbonate hardness that effects the stability of the ph?

Thanks for your comments ColinB. I can understand you thinking I am a complete newbie as I don't get on here as much as I did the old site. So little infact that Sue may have even forgotten about me (and boy did I used to hassle her with endless questions) 

Stuart.

Ah - thanks for the clarification.

Yep, GH includes KH, and it's KH that acts as the buffer and stops the pH dropping.

I've got one of these:



You have to read the small print for how to convert ppm to deg. very carefully as it's different for the two tests.

Something I only learned when my son worked for the water testing company:
GH is a measure of divalent cations, that's all. As far as most natural sources of water are concerned, that means calcium and magnesium, the most common divalent cations. GH does not measure monovalent cations like sodium and potassium, or anions like chloride or nitrate.
KH is a measure of how much acid is needed to drop the pH to a certain value. In natural water supplies this is virtually the same as measuring the amount of carbonate and bicarbonate in the water.

I always misunderstood GH. I thought it was a measure of everything dissolved in the water, including carbonate, but it isn't. This is why it's possible to have high KH and low GH. It's total dissolved solids (TDS) that measures everything.
But generally speaking, if you have hard water (high GH) you will also have have high-ish KH.


Sorry, bit of a rushed answer, I'm trying to get through all the posts while I've been away.


Edit to add:

I've just done my regular tests on my cycling tank, and did GH and KH as well. If you've read my cycling thread recently, you'll know I had a pH crash last week. When I set the tank up 6 weeks ago, my GH was 7^o German and my KH was 3^o German. (Multiply both by 17.9 to get ppm). The pH crahed because my KH is so low. I added bicarbonate of soda (chemical name sodium hydrogen carbonate) to raise the KH and prevent any further crashes during cycling.
The GH test I've just done gave 6 to 7 (by which I mean the colour changed slightly at the 6th drop and had changed completely with the 7th. So adding the bicarb did nothing for my GH. The only cation in bicarb is the monovalent sodium - and adding a lot of this has not affected the GH reading at all.
The KH test gave a reading of 11 to 12. This test changes from blue to yellow at the end point, it is much easier to see than the GH colour change. At 10 drops it was deep blue. At 11 drops it was green and at 12 drops it was bright yellow. So it was beginning to change at 11 but was complete at 12 so I'm calling that 11 to 12.

My cycling tank therefore has a KH almost double the GH which means the GH test cannot include KH, exactly what my son told me.

Good summary Colin, thank you. My post was a bit garbled as I was rushing