High KH

[Dave1NC]

I just recently had to downgrade my 90 gallon reef to a 28G Nano HQI. So far I like the tank, but I seem to having a problem with the KH. The tank has been running for about a month now and I used the live rock from my old tank and a half a bag of aragonite and fresh bag of new aragonite to feed it.

Using a fairtly new Salifert test kit my result was below 0.0. I also tested the CAL as it was 360. Does a Step 4 reading of below 0 = 16.0+ KH pose a serious issue? Any help would be a appreciated. Also please let me know if I should do anything to the water to lower the KH.

 

[bertoni]

Some water changes might help lower the dKH. What's been dosed into the tank, and what's the dKH of some freshly-mixed saltwater? Is tapwater being used? How about pH buffers?

 

[Dave1NC]

I purchase my water from a fish store that uses RO w/Instant Ocean. The water tests are perfect. I did some additional testing and my PH was 7.8/8.0 range. If I add some PH buffer, would that lower the KH?

 

[bertoni]

Adding a pH buffer will increase the KH. pH buffers are effectively high-pH alkalinity supplements. So the water from the store tests at a good dKH?

 

[Dave1NC]

0.42 (result 9.3 KH) was the result of the water I buy at the store. How much of a water change would you recommend in my 28G cube?

 

[bertoni]

I might do some 20-25% changes to reduce the level gradually. If the animals are all okay, the alkalinity might fall on its own well enough.

 

[Dave1NC]

Well this morning I got up and could not find one of my clown fish. I did not see his body, so he is either crab food or MIA. The 2nd mated pair is still alive and as far as I can tell the other fish are fine...

So I am going to do nothing except feed the corals and fish for 3-5 days and see what happens.