I can't figure it out...

[anthworks]

I have a 3 year old 150 with some SPS and some softies. I use a calcuim reactor ( single chamber with ARM media) with a steady drip and a effluent PH of 6.8 / 6.9. I also use one teaspoon of kalk in my top off water.

I did some tests a couple of days ago
PH 8.2 , Cal 430 Alk 7.7dkh.

I buffed my ALK up with Salifert Buffer to 9.0dkh. The next day it dropped to 7.7 again. I would increase my reactor but I dont want to blow out the calcuim.

Any reason my Alk is so low? I thought a reactor raises ALK AND Calcium.

 

[Randy Holmes-Farley]

First, 7.7 dKH is not low. I recommend 7-11 dKH.

That said, if you want it higher, then you just need to add more of both calcium and alkalinity each day, and the reactor is a good way to do that. In adequate dosing of both always is noticed first as alkalinity dropping.

Adding buffer each day will slowly deplete calcium as the alkalinity is disappearing along with calcium, even though calcium always drops more slowly on a percentage basis. The reactor will balance that almost exactly.

Increase the CO2 addition rate to the reactor and gauge the amount by the tank alkalinity after a few days. It won't blow out calcium. If you raise alkalinity by 1.3 dKH, the calcium will only rise by 9 ppm.
These resources may help:

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

Calcium Reactor setup calculator (CaCO3/CO2 reactors)
http://home.comcast.net/~jdieck1/reactor.html

 

[anthworks]

That's what I needed. thanks. Sorry about the duplicate post.

Regards

 

[Randy Holmes-Farley]

No problem. I just like to keep the conversation all in one place.

Happy reefing.