Dosing Carbo calcium alk is lowering.

Curtis Rose · Mar 31, 2020

Hey guys hooked up my doser abt two weeks ago. Dosing Carbo calcium started slow. I was having a drop of .5 alk a day. Mostly lps and a few sps. Tank has been doing well it’s two months old. Noticed a white bacteria building up in some places figured it’s from the small form of carbon dosing that Carbo-Calcium uses it Went away within a week or so. While I was dialing in my doser to keep my at 8.5 I had it there for a few days then it went up to 9 over a few days I cut down the dose and it’s held at 9 for a week I’m guessing my does was just a little high so cut the dose down again. Anyway gave it a few days before another test because I knew I was getting close. Tested again and it was up to 9.5 decided to turn off the doser and allow my alk to drop back into the range I wanted and try a lower dose. So far it’s been two days and my alk hasn’t come down at all. Should I wait it out? Calc is showing 420 and mag is 1320ish using Red Sea test kits not expired. Salinity is 1.026 nitrate is 5 phosphate .05 last water change was yesterday 5 gallons. Tank is a 50 gallon with a total volume of 40 gallons

rmurken · Apr 1, 2020

I have experienced similar fluctuations. My tank is a year and a half old. I have waited it out with no problem. Seems it has moods with respect to Ca/Alk. It’ll go at .5 dKh/day for awhile, and then .2 for awhile. It’s low demand either way, and fluctuations at that level are more noticeable than they are for people burning through 1+ dKh/day.

I’ve also experienced the upward alk drift. Again, just waited it out (took time). Nothing bad happened. Life went on.

Best not to chase numbers. Yours look normal. As long as your pH is 7.8 or better, I wouldn’t do anything. If it’s low, I’d skim or aerate to try to beat some CO2 out of the water.

Randy Holmes-Farley · Apr 1, 2020

Curtis Rose said:
Hey guys hooked up my doser abt two weeks ago. Dosing Carbo calcium started slow. I was having a drop of .5 alk a day. Mostly lps and a few sps. Tank has been doing well it’s two months old. Noticed a white bacteria building up in some places figured it’s from the small form of carbon dosing that Carbo-Calcium uses it Went away within a week or so. While I was dialing in my doser to keep my at 8.5 I had it there for a few days then it went up to 9 over a few days I cut down the dose and it’s held at 9 for a week I’m guessing my does was just a little high so cut the dose down again. Anyway gave it a few days before another test because I knew I was getting close. Tested again and it was up to 9.5 decided to turn off the doser and allow my alk to drop back into the range I wanted and try a lower dose. So far it’s been two days and my alk hasn’t come down at all. Should I wait it out? Calc is showing 420 and mag is 1320ish using Red Sea test kits not expired. Salinity is 1.026 nitrate is 5 phosphate .05 last water change was yesterday 5 gallons. Tank is a 50 gallon with a total volume of 40 gallons

it takes time for bacteria to consume the formate added and release the alkalinity. Go slow and give the tank time to respond. The formate doesn’t show on an alk kit.

Curtis Rose · Apr 2, 2020

Randy Holmes-Farley said:
it takes time for bacteria to consume the formate added and release the alkalinity. Go slow and give the tank time to respond. The formate doesn’t show on an alk kit.

This was my suspicion thank you it’s now 8.7 I’m gonna turn the doser back on soon with a lower dose than I had and wait a couple days see what it does. Thanks for chiming in Randy