kalk overdose leads to low alk?

[downset21]

My ATO pump went berzerk yesterday and the result was a dump of kalk into my display. The water became really cloudy and a white residue formed on everything except for the corals. I scraped the front of the glass as it seemed to calcify on that. I tested my water today and my alk dropped dramatically! (from 9 to 6)

All I can think of is that when the kalk overdosed it calcified all over the place and depleted the alkalinity. Do you have any other theories? So far all corals have the same color and polyp extension.

 

[blasterman789]

Kalk overdose (pH spike) causes calcium and alk to precipitate out as hard carbonate

The good news is it's a balanced fall out if I recall my chemistry right.

You really need to get dKH back up to running levels, but do so gradually.

 

[bertoni]

I agree with your theory. The white residue and the cloud in the water are both calcium carbonate, basically very fine sand. I'd dose the alkalinity up to the normal level with some baking soda, and check the calcium level. Most often, tanks come through this type of even without any problems.

 

[downset21]

thanks guys. It's at 7 now and I'll hopefully be at 8 tomorrow. I have a water change to do tomorrow as well so that might help move things along.

 

[downset21]

I agree with your theory. The white residue and the cloud in the water are both calcium carbonate, basically very fine sand. I'd dose the alkalinity up to the normal level with some baking soda, and check the calcium level. Most often, tanks come through this type of even without any problems.

I missed this part about baking soda. Would you recommend baking soda over the BRS two part Alk solution for this task? Or is there no difference?

 

[bertoni]

The baking soda is cheaper, and will affect the pH less, so it's easier to use for larger adjustments. The BRS (soda ash version) can spike the pH a bit. Baking soda will lower the pH a tiny bit. Both effects are temporary, though, in any case.