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GH and KH rising, help determining the cause

1453 Views 5 Replies 4 Participants Last post by  Diana
Just when I thought I had everything figured out with gh and kh, my 20L is giving me fits. I have a faucet style RO unit.

RO water
GH< 1
KH< 1

Tank water
GH 8
KH 8

I use a touch of prime and enough Seachem Replenish to get water to
GH 4
KH is normally 1

Substrate = Flourite and Pool Filter Sand
Rocks are Pagoda stones

Any thoughts on why my GH and KH are rising? The shrimp have been in the tank since August 20th and seem to be fine, but I want it lower for breeding/shrimplet survival rate.
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Do you have a nitrate test? Take the pagoda stone out of the tank and put a drop of #1 nitrate test on it. If it gets bubbly you have your answer, it is the culprit. If you put the stone back into the tank be sure to rinse and rinse and rinse it! Go ahead and test your sand as well but that isn't likely to be the problem as sand that dissolves wouldn't be very good filter media.
You can also take decor like the Pagoda Stone out of the tank and test it in a jar (whatever it fits in) of RO water. If the GH and KH rise then that is it.
If not, then keep on testing each item in the tank separately.

Test the substrate the same way, just in case...

I would rinse the tank water off whatever thing you are testing so the tank water with its high GH and KH do not mess up the tests.
Thanks, those are both good ideas. I had no idea my nitrate test would test that as well. I have a couple extra stones, so I'll probably just test on those first. Thanks for the help.

Nitrate bottle #1 is hydrochloric acid correct?
I think it is. Wear gloves, and eye protection would be a good idea.
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