Calcium sink hole?

[Jscwerve]

I'm having some problems with my calcium. It is disappearing at an alarming rate.

Tested today it is at 280. That's testing with both API and Red Sea

I had low calcium two weeks ago (about 280) and started doing 5 gallon water changes every day as well as dosing with SeaChem Reef Complete. I got the calcium up to above 350 (Still low, but better). Then I figured I'd slow the dosing and water changes.

After a week, I tested today.

Calcium 280
Kh 10
PH 8.2
SG 1.025
Nitrate 10
Nitrite 0
Phosphate 0

I do not yet have a mag test kit, but I'm going to try to pick one up tomorrow. In the mean time, what the heck? Not like calcium just evaporates!! :headwalls:

Total livestock of tank. 2 Clowns, 1 Watchman, A whopping total of 2 SPS, 7 LPS and a few softies. THAT'S IT!!!!

Where oh where does my calcium go?!?!?

Tank is 125 gallons with another approx 25 gallons in the sump. There's no way a few corals deplete that much calcium out of 150 gallons of water that fast, right? Then again, I don't know, I'm still new. The corals are growing fast and look happy.

Any advice is appreciated.

 

[gbru316]

Without knowing your magnesium, it's hard to know much. Magnesium plays a crucial role in tank chemistry regarding calcium and alkalinity.

 

[thegrun]

+1, until you have your magnesium in line it is impossible to raise your calcium.

 

[Jscwerve]

Ok, ran out and bought a kit. Mag 1230 so, low also right?

 

[Jeremiah_Conway]

The brand of salt mix you use is important also.
Test the new batch of water before water change so ya know what your gonna have to add.

 

[Jscwerve]

I've been using instant ocean

I'll mix a gallon and see what I get.

I am still curious as to why it would drop so drastically so quickly. I've been reading today and I've seen that coralline growth can deplete Mag and Cal so I'm wondering if maybe that's it. Coralline is growing INSANELY fast in the tank. I've been amazed at how fast actually.

Any good suppliment recommendations? What is the "industry standard" so to speak?

 

[thegrun]

1350 is ideal. Depeding on your corals and coralline algae drops of 20 or 30 ppm per day in calcium is fairly normal

 

[gbru316]

I am still curious as to why it would drop so drastically so quickly.

Start here:

Reef Aquarium Water Parameters

And FYI, I've found IO to be a bit low in calcium out-of-the-box. I like to keep Ca between 380 and 400 ppm, I typically measured 320-350 with IO. This doesn't mean you should find a new brand of salt, just that you need to consider the effect on tank chemistry when doing water changes. I just compensated by dosing some ice-melt (cheaper than aquarium additives) to bring it up to my target.

Any good suppliment recommendations?

Calcium chloride (ice melt):
An Improved Do-it-Yourself Two-Part Calcium and Alkalinity Supplement System

Since Ca is pulled out of the water, you're eventually going to need to make regular (daily) additions. Have you calculated your daily use yet? Take a Ca and Alk measurement one day, then repeat the measurements at the same time the following day. Don't make any additions or perform any water changes in between. This will give you a much better idea of what's going on, and will tell you how much you need to dose each day.

 

[Jscwerve]

Thanks all.

I had no idea that those parameters could drop that fast.

Plan of action is to dose and water change until I reach proper levels over the next week or so.

Then I guess I'll start dosing Kalk in my ATO.

Does that sound about right?

 

[Jeremiah_Conway]

I've been using instant ocean

I'll mix a gallon and see what I get.

I am still curious as to why it would drop so drastically so quickly. I've been reading today and I've seen that coralline growth can deplete Mag and Cal so I'm wondering if maybe that's it. Coralline is growing INSANELY fast in the tank. I've been amazed at how fast actually.

Any good suppliment recommendations? What is the "industry standard" so to speak?

Sounds right. I have noticed more coralline growth as I increase dosing

 

[gbru316]

Plan of action is to dose and water change until I reach proper levels over the next week or so.

Does that sound about right?

No need to change water to adjust Ca. Just dose. You might be doing more harm than good if the water used for the water change is lower in Ca than your target.

 

[morpheas]

Also, if i may chime in, you're magnesium being low could be a culprit to what's happening. Magnesium concentration in the water is directly related to calcium and carbonate solubility in the water. If it's too low then the calcium and carbonate (what we call alkalinity) will precipitate (rather than stay in solution for the corals to use and you to measure). I would consider dosing and bringing the magnesium up to 1300-1350 as a first step and see if that along with kalk or two part remediates the situation. Btw, are you using reef crystals from io?

 

[mike.p]

Start here:

Reef Aquarium Water Parameters

And FYI, I've found IO to be a bit low in calcium out-of-the-box. I like to keep Ca between 380 and 400 ppm, I typically measured 320-350 with IO. This doesn't mean you should find a new brand of salt, just that you need to consider the effect on tank chemistry when doing water changes. I just compensated by dosing some ice-melt (cheaper than aquarium additives) to bring it up to my target.



Calcium chloride (ice melt):
An Improved Do-it-Yourself Two-Part Calcium and Alkalinity Supplement System

Since Ca is pulled out of the water, you're eventually going to need to make regular (daily) additions. Have you calculated your daily use yet? Take a Ca and Alk measurement one day, then repeat the measurements at the same time the following day. Don't make any additions or perform any water changes in between. This will give you a much better idea of what's going on, and will tell you how much you need to dose each day.

Thank you for that link, very good article! I'm sure I'll need that at some point... Where do you get the Mag Flake? Home Depot doesn't seem to have it, and I can't seem to find any place online to order it from.

 

[homer1475]

Thank you for that link, very good article! I'm sure I'll need that at some point... Where do you get the Mag Flake? Home Depot doesn't seem to have it, and I can't seem to find any place online to order it from.

Same issue I had with doing randys DIY 2 part. I just ended up buying some bulk calcium chloride from BRS and using radys recipe for alk since baking soda is easy to source.

 

[Jscwerve]

Also, if i may chime in, you're magnesium being low could be a culprit to what's happening. Magnesium concentration in the water is directly related to calcium and carbonate solubility in the water. If it's too low then the calcium and carbonate (what we call alkalinity) will precipitate (rather than stay in solution for the corals to use and you to measure). I would consider dosing and bringing the magnesium up to 1300-1350 as a first step and see if that along with kalk or two part remediates the situation. Btw, are you using reef crystals from io?

That's the plan, picking up mag supplements today.

I've been using Instant Ocean, once it's done I'll be switching to reef crystals. I had planned to just add a coral here and there slowly. Then I brought the better half to the coral stores. She caught the fever so the tank got stocked pretty quickly. Lol

I figure it's going to be 4-5 days to get things up, then I'll do a test on subsequent days to sew how much I'm losing. Dose kalk after that accordingly.

Thanks for all the info everyone! So thankful for such a quick responding community.

 

[Jscwerve]

Oops double post.

 

[hkgar]

Instant Ocean salt mix is rated at 400 CA

 

[Reef Frog]

The OP's calcium consumption is about 10ppm per day. Depending on the corals and coralline algae growth in the tank, that isn't necessarily a crazy high amount. This is what my 6 year old 65 gallon reef consumes, and requires 1 teaspoon of supplement daily dissolved in RODI water.

Calcium consumption is good! It means stuff is growing. Now is the time to decide on how you want to add supplements. Your goal now should be to keep your big 3 parameters as stable as possible.