Calcium won't budge.

Mattdavid1212 · Jul 17, 2020

Hello all, to get straight to the point, I have a 91 gallon red sea tank with about 12-13 SPS corals in this tank, some bigger than others and a couple frags. I have been testing my calcium, magnesium and alkalinity every 2 to 3 days, yet my calcium is cruising around at 485 and my magnesium 1490 with my alk 8.2. I just don't understand why my calcium is not being consumed by the corals. Salinity 1.025. Any advice?

RobB'z Reef · Jul 17, 2020

I'm no calcium expert but i read that lower ph can inhibit calcification rates... is that in line for you?

Mattdavid1212 · Jul 17, 2020

PH 8.0

Ippyroy · Jul 17, 2020

How often are you doing water changes? What is the calcium level of the NSW? What are you using to test?

Mattdavid121 · Jul 17, 2020

Ippyroy said:
How often are you doing water changes? What is the calcium level of the NSW? What are you using to test?

Weekly 10% WC with the Red Sea salt.
Using Salifert. And even have the Hanna calcium and have gone into my LFS. Salifert is my main go to.

Mattdavid121 · Jul 17, 2020

Ippyroy said:
How often are you doing water changes? What is the calcium level of the NSW? What are you using to test?

Sorry didn’t answer the other question. The salt I mix myself at 68 degrees, it ends up 1.025 @ 420 calcium

Charlie’s Frags · Jul 17, 2020

Mattdavid121 said:
Weekly 10% WC with the Red Sea salt.
Using Salifert. And even have the Hanna calcium and have gone into my LFS. Salifert is my main go to.

Which Red Sea salt?

Charlie’s Frags · Jul 17, 2020

What are you dosing?

Ippyroy · Jul 17, 2020

My calcium barely changes and I do a 10 - 20% weekly water change.I just changed salt mixes so it is going up. I made the mistake originally of rinsing out the test cuvette for Hanna out in the tank. That threw off the results.

blasterman · Jul 17, 2020

You answered your own question. The water changes are replenishing calcium and SPS arent growing fast enough.

The rest depends on how fast the SPS are growing. If you have poccilopora or fast growing montipora with healthy white growth nodes calcium will slowly creep down.

A 91 gal tank has a lot of calcium

Ippyroy · Jul 17, 2020

^^ This is most likely the case. I would test NSW and see what it is mixing to. That will confirm it.

Mattdavid1212 · Jul 17, 2020

blasterman said:
You answered your own question. The water changes are replenishing calcium and SPS arent growing fast enough.

The rest depends on how fast the SPS are growing. If you have poccilopora or fast growing montipora with healthy white growth nodes calcium will slowly creep down.

A 91 gal tank has a lot of calcium

Appreciate it. I use the "red sea salt"
as far as corals in this tank: Red monti, Green monti, GSP on my back tank glass, leptoseris, 4 different montipora's
a frogspawn and an acans coral. I have not dosed.

SeaDweller · Jul 19, 2020

Mattdavid1212 said:
Appreciate it. I use the "red sea salt"
as far as corals in this tank: Red monti, Green monti, GSP on my back tank glass, leptoseris, 4 different montipora's
a frogspawn and an acans coral. I have not dosed.

There are two types of Red Sea salt: pro and regular, so we assume you’re using the regular blue bucket variety at this point, correct?

Mattdavid121 · Jul 19, 2020

SeaDweller said:
There are two types of Red Sea salt: pro and regular, so we assume you’re using the regular blue bucket variety at this point, correct?

Using the pro. Sor an SPS dom tank

Mattdavid121 · Jul 19, 2020

Mattdavid121 said:
Using the pro. For an SPS dom tank

Charlie’s Frags · Jul 19, 2020

Mattdavid121 said:
Using the pro. Sor an SPS dom tank

That’s probably your issue. The pro has elevated elements. Most sps collectors use the blue bucket bc it has lower cal and alk.

nereefpat · Jul 20, 2020

Mattdavid1212 said:
I have been testing my calcium, magnesium and alkalinity every 2 to 3 days, yet my calcium is cruising around at 485 and my magnesium 1490 with my alk 8.2. I just don't understand why my calcium is not being consumed by the corals.

Is alk being consumed? Every 1 dKH should also drop the Ca by about 7ppm.

Mattdavid1212 · Jul 21, 2020

nereefpat said:
Is alk being consumed? Every 1 dKH should also drop the Ca by about 7ppm.

Alk was 8.3 today. Calcium is still high, magnesium too. I am gonna let it ride, I am thinking my corals are still small so it is taking a while for consumption? Head scratcher for sure.

MightyMO · Jul 21, 2020

I ran coral pro for a year and a half in my 54 gallon corner. Finally ordered my test kit and my alk was at 14!!! I have since changed to blue bucket salt and am slowly bringing that number down. In the course of 3 weeks with a weekly water change of 20%. I have brought alk down from 14 to 11.9... Slowly working my issue out...
Now I would check my calcium if I were you right before my water change, see if they are up taking it... And I would STRONGLY caution dosing with the coral pro salt... Think that salt is for large aquariums packed with mature colonies of sps and encrusting lps... That's just my opinion on it, hope it helps!

Mattdavid121 · Jul 21, 2020

MightyMO said:
I ran coral pro for a year and a half in my 54 gallon corner. Finally ordered my test kit and my alk was at 14!!! I have since changed to blue bucket salt and am slowly bringing that number down. In the course of 3 weeks with a weekly water change of 20%. I have brought alk down from 14 to 11.9... Slowly working my issue out...
Now I would check my calcium if I were you right before my water change, see if they are up taking it... And I would STRONGLY caution dosing with the coral pro salt... Think that salt is for large aquariums packed with mature colonies of sps and encrusting lps... That's just my opinion on it, hope it helps!

Agreed. I have a 91g tank. 14 different SPS small colonies and frags. The alk has been staying around 8.3 to 8.5.