Calcium doesn’t drop, how to calculate other dosing

Neil Cohen · Oct 29, 2021

After following the Redsea formula, I found my Ca and Mg to be really high, 610 and 1600 respectively, tested by my lfs. So I followed their suggestions and bought Hanna checkers to make testing “easier” and more consistent.

LFS advice - Stop dosing Redsea a and c, a 20% and 50% water change with Redsea black a week apart. Wait a month and it would be consumed, they said.

A month later, Ca is now 550 but hasn’t moved in a week of testing with a Hanna checker since I started with the hannas.

Day over day it went up with nothing added but redsea b, nopox, a little aptasia-x (which I realize is basically Kalk but the tank is 100g) and trace abcd at 1.5 ml daily, per instructions.

Tank is all softies except for a couple of frags. Should I just let it go naturally? What about trace elements that are dosed based on Ca consumption?

thanks in advance, Redsea and dosers are all new to me. Working on stability.

Edit/addition info: Alk is 10.02. Been bringing it down from 11.3. Aiming for a stable 10.5. Don’t know how much that affects ca consumption. Zeroing on stablility, trying not to chase numbers. Ph, salinity, temp all stable. Nitrate is high but coming down. Phos was a little high but dropping. Softies don’t care but want to add sps/lps at some point. Killed too many to do anything till it’s all stable.

blaxsun · Oct 29, 2021

Just out of curiosity, what are you using for salt? How large is your tank, how frequently (and what volume) are you performing water changes and how much have you been dosing Foundation A, B and C?

Neil Cohen · Oct 29, 2021

Redsea black bucket, 95 net water volume. Infrequent water changes, outside of the two I just did. Was following the Redsea recipe for growth and color. Last month, no a or c, just 9ml c per day. Adjust to keep 10.5, or at least trying.

blaxsun · Oct 30, 2021

The Red Sea recipes are all well and fine, but they literally (at least in my experience) assume a tank wall-to-wall with corals, which is often not the case.

For my system (200 gallons total), I dose 48ml alkalinity and 8ml magnesium daily, and almost never dose calcium (it hovers between 465-475). This is on a mixed reef with mostly LPS/soft and some SPS corals.

I'd drop everything but alkalinity and your trace elements, and continue with 10% water changes every 1-2 weeks as you see fit. Worst case you end up with a bit more calcification and it takes your levels a few months to drop back down to where you want them.

Unless you're having massive coral issues I'd just let it naturally return.