How fast can you raise calcium?

[Riotjj21]

No more than 50 ppm per day, but I agree, something isn't adding up. I don't even know if its possible to have a reading that low.

@Randy Holmes-Farley

That's what the guy at the LFS said but he saw it with his own eyes. Lol

 

[Gtinnel]

Is there precipitation in the tank? How do your corals look?
I've always heard don't change alk more than .5 and calcium more than 50 per day.

 

[BrandonS]

Personally I wouldn't do more than 30ppm at a time but thats me. I have also not had any ill effects doing 50 at once but 200 is a bit much.

What is the time between your last test which looked normal and this one? new corals? any big changes?

 

[Biglew11]

Brs recommends about 50ppm per day.

 

[PeterC99]

Has anything change is your aquarium setup recently? New equipment, new media, manufacturer change in media, dosing, or supplements?

 

[Billldg]

K, let me ask you this...When was the last time you tested Cal and it was at your normal readings?

I am trying to get a gauge on how quickly it dropped.

 

[Riotjj21]

Is there precipitation in the tank? How do your corals look?
I've always heard don't change alk more than .5 and calcium more than 50 per day.

Everything looks fine. A freaking mystery. I raised it 100 ppm per a post on reef central. Well see how they look tomorrow. I lowered the lights significantly until this is resolved. Less light less growth less looking for calcium and carbonate, I'm hoping.

 

[Garf]

Everything looks fine. A freaking mystery. I raised it 100 ppm per a post on reef central. Well see how they look tomorrow. I lowered the lights significantly until this is resolved. Less light less growth less looking for calcium and carbonate, I'm hoping.

I don’t think it can just go down without using up over 10dkh in alkalinity. You checked salinity?

 

[Spare time]

I don't think it matters. I would just spread it out over a day to prevent precipitation where you dose it. It's not like calcium is going to be toxic or affect pH or anything.

 

[Riotjj21]

I don’t think it can just go down without using up over 10dkh in alkalinity. You checked salinity?

1.026

 

[Spare time]

But also, why can't two test kits be wrong? Why are we assuming that two cheap tests can't possibly be both incorrect

 

[Garf]

1.026

Can you check some freshly made up saltwater, for calcium?

 

[gbroadbridge]

Doesn't add up.

Check your salinity and check the calibration of your salinity measurement device.
I wouldn't just significantly raise Ca without independant verification of both Alk and Salinity

 

[Rmckoy]

No more than 50 ppm per day, but I agree, something isn't adding up. I don't even know if its possible to have a reading that low. What's your ALK at? K, just saw, your Alk is at 9.5 DKH.

@Randy Holmes-Farley

This was my original thought .
How is it even possible to have higher alk but cal so low .

referring to Randy’s handy calculator I use for dosing .
with alk at 7.5 dkh ( 134ppm ) the relative cal
Is 425

Without even checking cal I check alkalinity and dose both parts of 2 part knowing exactly what my calcium is going to be without testing

 

[Riotjj21]

Doesn't add up.

Check your salinity and check the calibration of your salinity measurement device.
I wouldn't just significantly raise Ca without independant verification of both Alk and Salinity

Done 1.026

 

[Riotjj21]

Can you check some freshly made up saltwater, for calcium?

Done. CA red sea coral pro 425. Supposed to be 450 at 78 and 1.026 according to label Did a 20 percent water change. We'll see tomorrow AM what it reads. Corals all look good so we'll see tomorrow.

 

[Riotjj21]

Has anything change is your aquarium setup recently? New equipment, new media, manufacturer change in media, dosing, or supplements?

Yes last Sat I started red sea coral pro salt. Did a 50 percent water change because my nitrates were at 20 ppm. Tested afterwards all parameters were fine. CA 450, dKh 9, mg 1350. I usually lose 30 ppm ca/day, Alk 1.5/day pH buffered at 8.2-8.35 swing per day

 

[gbroadbridge]

The higher Alk of Coral Pro will cause a Ca drop especially with a significant 50 percent water change.

It's not a good idea to do more than a 10-15% change when changing salt chemistry so much

 

[Randy Holmes-Farley Verified Community Expert]

Let's stay on topic. How much can I raise Ca in ppm a day?

It is on topic to very strongly drive home the potential for it to be test error, because you will create a problem that didn't exist.

If you do not know how it got there, it is likely a test problem. Calcium does not just drop 200 ppm overnight.

It would take a massive amount of alk dosing without any calcium. Like about 30 dKH worth.

But, if it really is that low, I'd raise it higher than the normal rate because it is very stressful. Maybe 50 ppm per day.

 

[Randy Holmes-Farley Verified Community Expert]

I don't think it matters. I would just spread it out over a day to prevent precipitation where you dose it. It's not like calcium is going to be toxic or affect pH or anything.

The calcium isn't, but the concern is impurities in it.