Really low calcium. Help!

ndz98 · Mar 29, 2017

I just tested my water and found that my calcium was extremely low. I tested twice just to make sure I wasn't going crazy but according to what the Red Sea calcium test kit says, 0.01 ml = 5 ppm CA and I used about .08. That brings me at about 40 ppm. Now before I just went and dumped calcium in, does this seem odd? I tested it a few days ago and it was no where near that low. But at the same time something isn't right I noticed because my zoas are receding a lot. What should I do?

AllSignsPointToFish · Mar 29, 2017

Zoas don't require too much calcium. What is your alkalinity running? Is it possible you added too much alkalinity and precipitated a bunch of calcium carbonate?

AllSignsPointToFish · Mar 29, 2017

The other thing you can do is calculate the calcium dose you think you need to add, add about 1/4 of that amount, and rerun the calcium test to see if it responds accordingly. Even if your test is lying, and extra 50-100 ppm of calcium over a short period should do little harm, especially to softies.

Also, check the expiration date on your Red Sea reagents.

ndz98 · Mar 29, 2017

AllSignsPointToFish said:
Zoas don't require too much calcium. What is your alkalinity running? Is it possible you added too much alkalinity and precipitated a bunch of calcium carbonate?

My alkalinity is right around 9 dkh. I didn't add an unusually large amount to where I would think it would precipitate the calcium.

AllSignsPointToFish · Mar 29, 2017

ndz98 said:
My alkalinity is right around 9 dkh. I didn't add an unusually large amount to where I would think it would precipitate the calcium.

Okay, that's good. Do you topoff with limewater? How big is the tank?

ndz98 · Mar 29, 2017

AllSignsPointToFish said:
Okay, that's good. Do you topoff with limewater? How big is the tank?

I top off with RO/DI. Filters are all brand new. The total volume of water is about 34 gallons.

AllSignsPointToFish · Mar 29, 2017

ndz98 said:
I top off with RO/DI. Filters are all brand new. The total volume of water is about 34 gallons.

Gotcha. Did the Red Sea powdered calcium reagent clump into a ball when you added to the test tube?

Randy Holmes-Farley · Mar 29, 2017

Get a new kit (or carefully read the directions on this one). Test some new salt water.

There's more chance you'll be hit by a meteor while reading this than that the calcium is 40 ppm. lol

ndz98 · Mar 29, 2017

AllSignsPointToFish said:
Gotcha. Did the Red Sea powdered calcium reagent clump into a ball when you added to the test tube?

No the calcium reagent dissolved evenly.

ndz98 · Mar 29, 2017

Randy Holmes-Farley said:
Get a new kit (or carefully read the directions on this one). Test some new salt water.

There's more chance you'll be hit by a meteor while reading this than that the calcium is 40 ppm. lol

Yea I figured 40 didn't make sense at all. Hopefully there's not a meteor shower tonight

ndz98 · Mar 29, 2017

Okay so luckily I have another test kit on hand so I decided to use it and see if it would give me a different result. Sure enough it did. I got a reading of 430 ppm calcium. I'm not entirely sure why I was getting bad readings with my other kit. The expiration date wasn't for another year.

Randy Holmes-Farley · Mar 30, 2017

ndz98 said:
Okay so luckily I have another test kit on hand so I decided to use it and see if it would give me a different result. Sure enough it did. I got a reading of 430 ppm calcium. I'm not entirely sure why I was getting bad readings with my other kit. The expiration date wasn't for another year.

Sounds good.

Happy Reefing.