Low alk issues

[John Lohsr]

I have a 90 gal tank with a 40 gal sump which is half full so 20 gals. I'm having trouble getting my alk to come up. My cal is 440 and has been there for at least 4 days. My mag is 1300. I want to start using kalk in my ATO. My alk was 5dkh so I started to try to bring it up with sodium bicarbonate and using BRS's calculator I am dosing 6 oz of sodium bicarbonate to raise the alk no more then 1.4 dkh per day. I test and then dose first thing in the morning and then test again in the afternoon to see where I'm at. It comes up a little more the 1 dkh but when I test in the morning its down almost 1 dkh again. My tank is lightly stocked, 100 pounds live rock and lots of coraline algae. Is it possible that the tank could be using 1 dkh per day? Should I be dosing in the morning or at night? I'm not dosing any calcium and its staying at 440 ppm. I'm using new salifert test kits that aren't expired. Any help would be greatly appreciated.

 

[CodyRVA]

How old is the system? What salt mix are you using? What percent and rate of water changes are you doing? What kinds of corals are you keeping?

 

[John Lohsr]

This tank is an uograde from a 49 gal so half the live rock is from that tank. This tanks been up for 4 months. I use reef crytals and do 10o/o water changes a week. I have two frags of sps, a monty red cap, pink digi. Two frags of lps an acan and a favia. And several zoas and some Kenya tree softy. My salinity is 1.025 by refractometer.

 

[CodyRVA]

Likely due to a young system, but try upping your dosage for ALK little by little and test accordingly; see what you get...

 

[saltyfilmfolks]

This tank is an uograde from a 49 gal so half the live rock is from that tank. This tanks been up for 4 months. I use reef crytals and do 10o/o water changes a week. I have two frags of sps, a monty red cap, pink digi. Two frags of lps an acan and a favia. And several zoas and some Kenya tree softy. My salinity is 1.025 by refractometer.

What size WC is that.?

RC Is fairly high Alk.
So you alk that low and tha cal that high is really really odd.
I'd get a second opinion on the test or re do if you haven't.