Constant Low Alk in newish tank

[Aaron75]

So I have a 15g which I know will lead to some instability but this one is stumping me. Randy kind of started me on the topic so I'd like to discuss further. My Alk stays around 6. Yesterday i measured and it was 4.9. Did a 20-25% water change and 24 hours later it is 5.7. Using reef Crystals, fresh mix was 11.2. Now where Randy lost me is about a correlation with nitrates and Alk. And another thing about precipitation. Can I dose All for Reef and be fine, or is there more to it? Ultimately I'd like a full break down on cause and effects and just to learn what I can/ should do.

 

[Randy Holmes-Farley Verified Community Expert]

Bump

I'd boost the alk, but otherwise those valuss are OK.

 

[Aaron75]

I'd boost the alk, but otherwise those valuss are OK.

So baking soda?

 

[Randy Holmes-Farley Verified Community Expert]

So baking soda?

That's certainly a fine choice, as are lots of other choices. If you have some at home., I'd use that. :)

 

[flatlander93]

Those numbers match exactly what I am seeing too. I’m adding sodium bicarbonate solution note to bring all up to an acceptable range. Softies all look great, lps good, SPS not great.

 

[Aaron75]

Those numbers match exactly what I am seeing too. I’m adding sodium bicarbonate solution note to bring all up to an acceptable range. Softies all look great, lps good, SPS not great.

I started slowly adding baking soda yesterday, all my corals look fine, just have 0 growth.

 

[flatlander93]

Added a fair amount of the bicarbonate and still not going up. Does this stuff take a long time to show up in tests? Still at 5.1 (Hanna)

 

[Aaron75]

Added a fair amount of the bicarbonate and still not going up. Does this stuff take a long time to show up in tests? Still at 5.1 (Hanna)

My results were clear after a couple hours. Did you calculate how much you need? Are you mixing it in water and then adding?

 

[Icryhard]

Added a fair amount of the bicarbonate and still not going up. Does this stuff take a long time to show up in tests? Still at 5.1 (Hanna)

First of all, be careful how much you do (alk should go up or down with 1 max) and yes, to some extent it'll take some time. For example, I did 5 gram of it in my 120 gallon tank and 30 minutes ago I tested and my alk had gone up with 0,45. Also, try to spread it so it doesn't clump up. Best thing would be some aquarium water, throw the baking soda in it, steer it properly and then pour it back into your aquarium.