Alkalinity and Calcium

MB_Reef · Jun 30, 2023

Hello all,

Is there any reason why the alkalinity in my tank drops everyday, but calcium stays stable? I am testing alkalinity and calcium daily, at the same time everyday, using Hannah checkers. Salinity is constant. Calcium results are very consistent, often getting the same exact result as the day before, or +/- 5ppm. I am using Seachem 2 part solution and I am only having to dose the "part 2" to maintain alkalinity since Calcium doesn't change. This has been going on for weeks.

Why am I not having any calcium consumption?

Propane · Jun 30, 2023

Drops or fluctuates?

Brandont21 · Jun 30, 2023

does growing coraline deplete calcium?

Propane · Jun 30, 2023

If you are dosing calcium and it tests the same everyday that would prolly mean you are dosing the correct amount. Yes coralline will consume calcium.

Randy Holmes-Farley · Jun 30, 2023

MB_Reef said:
Hello all,

Is there any reason why the alkalinity in my tank drops everyday, but calcium stays stable? I am testing alkalinity and calcium daily, at the same time everyday, using Hannah checkers. Salinity is constant. Calcium results are very consistent, often getting the same exact result as the day before, or +/- 5ppm. I am using Seachem 2 part solution and I am only having to dose the "part 2" to maintain alkalinity since Calcium doesn't change. This has been going on for weeks.

Why am I not having any calcium consumption?

How big of an alk drop?

It is far easier to detect a daily alk drop than the expected amount of calcium drop.

Seachem two part is also not designed properly for 1:1 dosing despite their claims. Hard to u set stand how they messed that up.

Miami Reef · Jun 30, 2023

Brandont21 said:
does growing coraline deplete calcium?

Yes.

Randy Holmes-Farley · Jun 30, 2023

Brandont21 said:
does growing coraline deplete calcium?

Yes, just like corals and abiotic precipitation of calcium carbonate: 18-20 ppm calcium for each 2.8 dKH of alk consumption.

MB_Reef · Jun 30, 2023

Propane said:
If you are dosing calcium and it tests the same everyday that would prolly mean you are dosing the correct amount. Yes coralline will consume calcium.

I am not dosing any calcium. Only "Part 2"

MB_Reef · Jun 30, 2023

Randy Holmes-Farley said:
How big of an alk drop?

It is far easier to detect a daily alk drop than the expected amount of calcium drop.

Seachem two part is also not designed properly for 1:1 dosing despite their claims. Hard to u set stand how they messed that up.

I try to keep alkalinity at 9.5. If I don't dose anything, I usually go from 9.5 to 8.8 in 24 hours.

Propane · Jun 30, 2023

MB_Reef said:
I am not dosing any calcium. Only "Part 2"

my bad you did say that. What kind of corals do you have?

MB_Reef · Jun 30, 2023

Propane said:
my bad you did say that. What kind of corals do you have?

Mostly SPS and LPS with some Zoa's. It is a small 10g with about 25 frags in it.

Propane · Jun 30, 2023

Seems like that many frags would be using calcium if they are growing. If you know they are growing then maybe your test kit is off.

vetteguy53081 · Jun 30, 2023

MB_Reef said:
Hello all,

Is there any reason why the alkalinity in my tank drops everyday, but calcium stays stable? I am testing alkalinity and calcium daily, at the same time everyday, using Hannah checkers. Salinity is constant. Calcium results are very consistent, often getting the same exact result as the day before, or +/- 5ppm. I am using Seachem 2 part solution and I am only having to dose the "part 2" to maintain alkalinity since Calcium doesn't change. This has been going on for weeks.

Why am I not having any calcium consumption?

What method are you testing?
Alk and CA work as a balance and reasons alk is lower can be of course coral consumption, the salt used is high in calcium or if you just added calcium prior to testing, addition of ca can lower alk level