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kH or no kH that is the question....?

Gadget

Member
Joined
17 Apr 2021
Messages
45
Location
Sheffield
So as my new tank cycles, having added Tropica Substrate and Aquarium soil, I expected that I would have to keep an eye on the kH and gH for the first while. However, when testing with the Aquarium Labs dropper test set, my gH shows at 6 (which is in the correct range for the type of fish I am looking to keep), but the kH shows as not existing, as in 1 drop turns the yellow to blue. So I thought wow, this Tropica has really taken a hit on the water... My pH tested at 6, but after looking at the kH reading, I am concerned it could be lower, as 6 is the lowest the test goes....

I had not tested the kH on the tap water before for one reason or another, so decided I would test that to see just how much it had dropped... That also reacted in exactly the same way.....

So it appears the local tap water has no kH whatsoever. I figure I need to use a buffer, but can anyone tell me which they recommend the most? Have seen this one....

1620141761740.png

But don't know anything about this company? It seems a fair bit cheaper than Seachem (which just about anything else is), but is it decent? Any other recommendations? I want to keep Amizonian type fish, so Tetra and APistogramma for the best part, so low pH is not too much an issue, but would like to stabilise it around 6.6 to 6.8.

Cheers
G!
 
Salts are salts and plants dont care about brand, so if you after KH then
1620147526294.png


So thats a level teaspoon per 1KH per 100Litre WC, if you have a nano tank post your WC volume and I will work out the maths or a DIY solution for you to use.;)
 
Hi gadjet the solution to raise the kh lies above with zeus.

Personally I think the reason for your low ph and low kh is related to your tank still cycling and possibly substrate.
There's allsorts of chemistry going on in there at the minute and I suspect that if you give it a few weeks things will settle down.

Either way don't waste your money on expensive buffers.
 
Personally I think the reason for your low ph and low kh is related to your tank still cycling and possibly substrate.
There's allsorts of chemistry going on in there at the minute and I suspect that if you give it a few weeks things will settle down.

Thanks for the reply... That was what I thought at first until I measured my tap water which also registered zero kH. I have heard of people using bicarb, but I thought that was sodium based, and adding that much sodium would be problematic?

Regards
G!
 
It could well be your tap water is around 1kh (mine is) and your test kit can't measure to those degrees of accuracy.

Yes its not advisable to add sodium bicarbonate to your tank but adding potassium bicarbonate is fine.
 
Ok, I've never heard of Potassium Bicarb as a product as such... Is it easily available?

Cheers
G!
 
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I'm assuming you are using the API tests? You are looking for blue turning to orange to determine Kh degree.

Both the Gh and Kh tests are value recorded when the are there base colour.

Sorry, its the NT Labs test kit. Their reading says 6 - 8 drops should be the point of change and that 3 - 4 is acceptable for acidic water fish, but my test is rapid change at one drop. No hesitation or slow change, but strait to the opposite colour. That is both for the tank AND tap water.

Cheers
G!
 
Don't believe the hype Gadget, my tank kh is 1 ~ 2 and the fish are doing fine, NT labs are just trying to sell you more of their kh buffer products.

Taken from nt labs site.

What is the correct KH level?
This test kit measures KH in dKH (where one dKH = 17.8 ppm as CaCO3). It is essential to maintain a minimum KH level of at least 4 dKH at all times. A KH of between 6 and 8 dKH is more desirable.

What do I do if the KH level is wrong?
Check the KH level of your tap water. If the level is above 6 dKH, then regular water changes should keep the KH value in the aquarium topped up at a reasonable level. If the KH value of your tap water is below 6 dKH, you will need to add a KH buffer such as KH Up – pH Stabiliser to your aquarium/pond.
 
Don't believe the hype Gadget, my tank kh is 1 ~ 2 and the fish are doing fine, NT labs are just trying to sell you more of their kh buffer products.

I am more just concerned about stabilising the pH which is why I am looking to buffer it since at best there is 17.8PPM which is way too low to hold the pH at 6.6 to 6.8, especially with Mopani wood and and Tropica soil in there. I thought about adding a small piece of rock to leach some minerals into the water column to act as a buffer too, but not sure which would be ok, and it is less controlable. But with such low kH and a pH showing at 6 (which is the lowest it will read at) I think it is definitely in need of 'buffering', however, if the Potassium Bicarb method will do the job, then that is great.

Cheers
G!
 
How much water are you changing in the tank Gadget?

You can check your water report and that should tell you your average pH levels of the tap water, I'd be surprised if its at 6. Is you're supplier Yorkshire water? If so just put a postcode into this link.

Once your tank stabilises the ph may well rise a good bit anyway.
 
Its been running for about 10 days now, and I have done two water changes so far. One was about 50%, then the next was about 40%. I am going to do another tomorrow. I have not yet tested the pH of the tap water, which I do expect to be higher than 6, but the tank is reading 6. This is what that site above states....

1620156695348.png

Regards
G!
 
For now I'd stop worrying about ph or kh.
It looks like the tap ph is 7.5.

Your tank is in the early stages of cycling, do more regular water changes and once things settle in another couple of weeks you should see the ph rise and things start to get on a more even keel.
 
Hi all,
I am more just concerned about stabilising the pH
The pH won't ever be stable in <"really soft water">, it isn't a problem. As soon as I found out that aquascapers who add CO2 have a drop of one pH unit before "lights on" and a rapid rise of one pH unit at "lights out" with healthy fish, you know that pH fluctuation isn't the issue.

The problem is with pH as a measurement in that it is both <"log10 value and a ratio">. You can't extrapolate between hard water and soft water

Rather than get hung up over pH levels I just look at changes in ionic water chemistry ("salts"). As long as you don't have large changes in salts level your fish are fine.
  • In hard water you need a large change in water chemistry to cause a small change in pH, and
  • in soft water small changes in water chemistry cause large changes in pH.
cheers Darrel
 
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If it helps, my new tank with ADA Amazonia produced a ph of 5.4 early doors. It now swings between 5.8 and 6.8 a couple months on with the CO2. I use RO water and remineralise to approx TDS 120 per the Green Aqua way, they also advise not to worry about pH too much with this setup, so I don’t and the plants and critters are merry 👍
 
Honestly I am very jealous!! You could keep some really lovely South American and Asian softwater fish in there and they'd love it.

Yer, I used to breed Apistogramma's a long time ago, and this would indeed be perfect for them, though I still had a kH reading albeit low, but never experienced this where the tap water shows dKh of 1 or less. I guess living next to the Peak (Peat) district has its pluses. Anyway, I'll get some Potassium Bicarb and add a little.

Thanks for all the help folks.
Regards
G!
 
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