Calcium Question

[U4BOYZ]

I tested my calcium a few days ago and it was 400mg. So I added 1 tsp. for my 120 gallon tank. I noticed some of my corals weren't opening yesterday and today so I tested it again today and it's down to 320mg! How can I have such a drop in calcium in a few days if I had added a tsp. of calcium? I'm sure both my tests were accurate---I not only tested them twice but I'm a very slow and careful tester (I was a nurse). Thoughts? Is there another test I should be running to make certain I'm alright? The only other test that was off was my KH. It's down to 5 drops. I guess I need to add a KH booster? Thanks.

 

[yote]

Yeah,You need to bring your alkalinity up a tad:D It really should be between 8 and 10 DKH.
Something else you really need to test for,is magnesium.If its low,you wont be able to keep calcium and alkalinity stable.
What brand salt are you using?

 

[U4BOYZ]

Interesting. I'll test for magnesium next. I'm use Oceanic Natural Sea Salt Mix.

 

[yote]

In that case,just do a big water change:D
If I remember right.When I was using Oceanic salt,it normally had 9 DKH with a calcium of 500 in a fresh mixed batch of water.Cant remember what the magnesium was.

 

[U4BOYZ]

Yote your knowledge is incredible! When I grow up, I want to be just like you!!! :)

I have to get a mag test kit...it doesn't come in my big chemistry kit. I'm also going to pick up a KH booster while I'm there.

I added calcium and have since re-tested...it's back up to 420mg. Thanks for all of your help!

 

[Bifferwine]

Calcium at 400 is just fine -- you don't need to add anything to bring that up. In fact, if you have softies and LPS corals (no SPS), anything above 300 will be just fine. They do not require a lot of calcium.

If you have a lot of coralline growing, that may be what is sucking up your calcium.

 

[yote]

Ursula,Just run down your local wally world and pick up a box of plain old arm and hammer baking soda. Then use this calculator Reef Chemistry Calculator to figure out the dosage.
Just mix however many teaspoons it says in a glass of RO water and dose a little bit at a time over the course of a couple of hours.

 

[U4BOYZ]

Using the calculator....I was at 5 KH and I wanted to go to 8 KH....for my 120 gallon tank....it told me to add 8.6 tsp. Does this sound right? Seems like a lot to me. I just want to make certain I did it right...I've never used one of these calculators before. Love the money saving tip, Yote. Thanks.

 

[U4BOYZ]

Interesting Bifferwine. I do have a lot of coralline rock in my tank I guess. At least it looks like the google images I found. I'll attach a photo of one of my living rocks. I think it's a coralline rock. Are these rocks what are sucking up all of my calcium? Thanks.

 

[U4BOYZ]

Here's a photo of my coral that made me think something was wrong. It closes-up once and awhile...but this morning it was closed-up and looking limp. Now, as you can see, it's perked back up (maybe from adding the calcium?). I'm waiting for it to open again...I hope not too much damage was done. Is this what you mean by a soft coral Bifferwine?

 

[Bifferwine]

That's a leather (a soft coral), it wouldn't be affected by calcium -- it doesn't have a calcareous skeleton, so it doesn't use calcium in any appreciable amount. It is normal for leathers to slump over and get limp once in a while.

The purple stuff growing on your rocks is coralline -- not the rock itself, but the purple coating on the exterior of the rock. That uses calcium. Coralline is a good thing -- it's a sign of a healthy tank. And where coralline is growing on rocks, it makes it harder for nuisance algaes to grab ahold.

 

[U4BOYZ]

Well I have plenty of coralline...so I think you found the calcium culprit. :) Maybe I'll start checking my calcium twice a week now?

I'm thinking of using baking soda to raise my KH as Yote suggested. Have you had any positive/negative experiences with this? Thanks.

 

[Bifferwine]

I don't know -- if you don't have any stony corals (SPS), I wouldn't even bother checking calcium at all (I don't for my tank). Regular water changes will keep it in balance for soft corals and LPS corals, which don't require a lot of calcium. Checking it once a week is fine, but I wouldn't bother doing it any more often than that.

As for the baking soda, I've never had to use it myself but tons of people have. And it is by far the cheapest solution to alkalinity problems.

 

[parrotchute]

I don't know -- if you don't have any stony corals (SPS), I wouldn't even bother checking calcium at all (I don't for my tank). Regular water changes will keep it in balance for soft corals and LPS corals, which don't require a lot of calcium. Checking it once a week is fine, but I wouldn't bother doing it any more often than that.

As for the baking soda, I've never had to use it myself but tons of people have. And it is by far the cheapest solution to alkalinity problems.

To keep my pH up, I euse ReffBuffer 8.4, I add some to each water change and it seems to work pretty well.

I hate testing, particularly for calcium, such a pain!!!! I wish there was an easier way to quickly see if your calcium is low....

 

[U4BOYZ]

That's the funny thing...my PH has always been fine. Somewhere between 8.4 and 8.5. I've been watching it closely since my KH is so off....

 

[parrotchute]

Sure your test kit for kh is good?

 

[U4BOYZ]

I did think of that. I'm assuming it is. I've only have the kit for 4 months...so hopefully it's still okay. It's the first time it's read so low....

 

[parrotchute]

Get another kit and compare the results, or bring a sample to the lfs for checking.

 

[yote]

You could very well have a bad test kit.I've seen that happen a lot.

But if the kit IS good,dont try to bring the alkalinity up all at once.Just raise it something like 1 or 2 DKH every 3 or 4 days untill you hit that 8 to 9 DKH target zone.