Where is my Alk going?

[Jeff D2]

I have a new 7 gallon Nano about 3 weeks old. It was set up with LR / LS from my main 3 year old 100 gallon. Cycle time was less than 48 hours and only saw a small bump in nitrite. All the corals are softies with the exception of a branching hammer.

Salifert test kits.

Ammonia 0
Nitrite 0
Nitrate 2
PH 8.3 seems stable haven't noticed any swings
Ca 530+ highest reading at end of week one was 560-570
Alk 6dkh low, 11dkh high after dosing Alk boosters
SG. 1.025
Temp 80 degrees

All the life seems happy, but coraline growth is very slow. Might have a little PO4 problem.

I have tried dosing B-Ionic Alk part only, SeaChem Reef Builder, SeaChem 8.3 Buffer. All of these increase my Alk to about 10 to 11dkh but within 48 hours the Alk has rebounded back down to 6 to 7dkh. When I dose, my tank stays clear, and I haven't seen any snow.

I am not dripping Kalk for makeup water, was hoping to control Ca/Alk with B-Ionic.

Any clues on what may be eating my Alk?

Thanks for any help, this is a problem I haven't fought before.

Jeff

 

[randy holmes-farley]

Calcification will obviously drop alkalinity. So will abiotic precipitation of CaCO3, and the high calcium may encourage abiotic precipitation..

The early stages of the nitrogen cycle, stopping at nitrate, can also deplete alkalinity.

The alk drop that you see is about what I see in my aquarium.

Perhaps you just need to add more alkalinity supplement.

 

[Jeff D2]

Thanks Randy,

Guess I was just a bit confused when I didn't see any substantial drop of Ca with the ALK drop, and it just seemed strange to be adding so much buffer to such a small tank.

I have found that the Seachem 8.3 buffer I have been using contains Borate. Should I switch to something else so I don't start getting false ALK readings?

Thanks again,

Jeff

 

[randy holmes-farley]

The Seachem buffers for reef systems don't have borate, as far as they've told me. But the Seachem Marine Buffer for fish only tanks does. I'd avoid the excess boron.