Small tank alkalinity too high...

[kalare]

I recently set up a small 30g reef. Wanted to try something apart from my larger tanks, but in the end, I still ended up putting every piece of equipment you would find on a 120 on the 30. I set the calcium reactor to around 30 bubbles/min and 40ml effluent. In the last 4 days, my calcium has gone from around 350 to 460 and alkalinity from around 10 to over 14! I'm wondering how I can keep the calcium over 400-420 without having such a high hardness. Most of the corals are not liking it, though on prostrata has shot out 2 branches in 2 days, the rest are all closed up.

The water I use is NSW from scripps, about 8 alkalinity and 340ish calcium. RO water for topoff.

Over all the years, I've never had this problem, it's almost always too low. I have no clue what's going on.

 

[bertoni]

I would guess that you could turn off the reactor to let the calcium and alkalinity drop. You could dose calcium when it drops below your target. When the alkalinity is at your target, then you could start dialing the reactor back up, starting at a much lower bubble rate.

What is the pH?

 

[Randy Holmes-Farley]

In the last 4 days, my calcium has gone from around 350 to 460 and alkalinity from around 10 to over 14!

The reactor is greatly overdriving the system. I agree that turning it off is a first step, and getting an actual alkalinity reading is next. Add a second syringe of titrant if necessary, and add the values together. Then we can figure out how to proceed (probably by just monitoring for a few days).

This article may help:

Solving Calcium and Alkalinity Problems
http://www.advancedaquarist.com/issues/nov2002/chem.htm