Calcium help!!

[Longnose Hawkfish]

Hey everyone! Hope you are having a great day! Anyways, I tested my water and my calcium was 340. so I added some kent marine calcium, and I checked my calcium about 16 hours later and now it's 300. Why? I have a 14 biocube, and a added about half a cap of the calcium, but my number seemed to lower. Can some one please help? Will my corals be fine for the time being?

 

[cmaxwell39]

Low calcium will not kill your corals, but it may stunt the growth of corals that build a calcium carbonate skeleton (LPS/SPS). As far as why your calcium seemed to get lower when you added a calcium supplement, the answers to a few questions may help determine what is going on.

First of all what test kit are you using to measure calcium?

How old is the test kit and what is the expiration date?

What was your test results for your alkalinity and magnesium?

 

[Longnose Hawkfish]

Thank you for the fast response.
Now to answer those questions, it's an API, which I know are not the best, and it's maybe three months old. I also had my lfs test calcium and it have the same as my test kit. An alkinity was 9, and mag is in the acceptable range.

 

[cmaxwell39]

That is really weird. How long after you dosed the calcium supplement did you wait before testing? If you run the test twice back to back do you get the same results both times? I am leaning toward a bad test result, but I am not sure.

I would have thought if you overdosed the calcium supplement that you would have noticed a precipitation event (would look like it was snowing in your tank), so I don't think that is it, but I am still not sure why the calcium would test lower after you dosed a supplement to bring it up.

When you say mag is in the normal range, do you know what that would equate to in ppm? 1200-1500 is normally considered good, if it is down around 1000 ppm, you may want to bump it up a little bit.

What type of corals do you have in the tank? If you only have soft corals such as zoas and mushrooms you may not need to worry about it and bring it up over time by doing some waterchanges with a good quality salt.

That would be another question, what salt mix are you using and have you tested the levels of the newly mixed saltwater?

 

[Longnose Hawkfish]

I waited 16 hours to test, and I did three tests, all giving me 300 calcium. I know my mag lv is in that range, and I have zoas, mushrooms, sps and lps in my tank. In all 19 different corals. Umm I'm not 100% about salt mix, I but the salt water from my lfs, but normally I do water changes every other day, and that keeps my levels up, but I decided to go for a week without doing one, and my calcium level was the only one that was bad afterwards. It was getting hard doing so many water changes with school, but that's what I might have to do.

 

[PaulKreider]

I have the API calcium test kit and its never been anywhere near close. My lfs said try putting in about 15 drops than let it it for a minute before adding another and continue that way, the api kit seems to take a little longer to react.

 

[Longnose Hawkfish]

Ya I should try investing in something better. but by 15 drops mine changes colors into te blue when it's done.

 

[PaulKreider]

Mine always reads 900calcium... so Its clearly off, I just go by looks and alk.

 

[Longnose Hawkfish]

Lol!! But I don't know what to do now. I think I might just do a water change today.

 

[Reefing Madness]

Depending on what you have in the tank, your corals can be using it up, and you did not dose enough the first time to put a dent in the number. I'd raise your dosage a bit, and retest in an hour.

 

[glb]

I just bought the salifert ca test kit and really like it. I started with API but found they weren't that accurate.

 

[Longnose Hawkfish]

Ya haha it has not been workin for me. is there any digital testers?

 

[mtnrunner]

Take a look at Hanna Checkers.

 

[ritter6788]

What brand of salt are you using?

 

[Longnose Hawkfish]

I think instant ocean

 

[ritter6788]

340-360 is typical calcium level for IO salt. Your test appears to be in line. I'll also add, 1/2 cup of calcium is a lot in a 14 gallon tank and you may have caused calcium precipitation which is why you got a lower reading after dosing.

 

[Longnose Hawkfish]

Ok thanks, and I think I said half a cap. Is that still a lot?

 

[ritter6788]

Ok thanks, and I think I said half a cap. Is that still a lot?

Lol, sorry I misread. Half a cap isn't too much.

 

[Longnose Hawkfish]

Haha it's fine! Any ideas on what I should do? Are digital calcium checkers better than chemical?

 

[ritter6788]

Any ideas on what I should do? Are digital calcium checkers better than chemical?

You could simply change to a salt with higher calcium such as Reef Crystals. Unless your tank has sps and/or clams you likely won't have a lot of calcium demand.

I use the API myself and haven't had any issues with it. Make sure to follow the directions exactly though. Shaking the bottles is important. The Hanna checker is good but it's a pain to use. I get the same numbers with my API as the Hanna checker so I use the API since it's easier.