I can't raise my alkalinity level!! Help!

[bertoni]

Calcium at 450 ppm should be fine, even for higher levels of alkalinity than you're reporting. If the magnesium level is exceptionally low, that might be an issue, but that's extremely rare, as far as I can tell.

 

[Tek]

Mg is right around 1400. I was able to keep ALK steady at 8.7dkh today. My SPS must be growing faster and up taking more than my last calculations. I spread out the dosage to 12 times a day during during lights on.

 

[bertoni]

I agree that increased growth is most likely the issue.

 

[Tek]

Adding 4 new frags and faster growth was exactly the issue. I recently upgraded to better lighting/reduced phosphates and things have taken off. I have it dialed in now at a constant 9.0dkh.

 

[puffster]

Here is something that you might try to do to alleviate the situation at hand. The problem might not be the dosing amount or when you dose. From the looks of it, there are a lot of correlating pieces of advice that are proven and of good value. The problem might just be a slow build-up of Co2 in the tank. Carbon Dioxide turns calcium carbide into carbonic acid thus dropping PH and lowering the Alkalinity. This can be reversed by opening a window and positioning a fan over the tank to draw in the fresh oxygen and expel the Co2. Even thought it is on a small scale, it can be a detrimental demise of a reef tank. This usually happens in the winter months when we close the doors and windows to keep the snow out but can happen in any area that is not well vented with fresh air. I hopes this helps, good luck.

 

[Tek]

I have heard of that also but my house is well ventilated. It hasn't gotten cold yet so the window is open a few times a week. Ph is usually on the high end and never drops below 8.0 at night. My alk only drops during the day so it is the corals using it up. I dose from 8am to 12am. The alk doesn't drop at night.