Where oh where has my Calcium gone?

[Jason82]

I have a newly started 75 gallon tank. 2" of crushed coral and at this point only 40 lbs of dry rock. the rest of my live rock from another tank is cooking.

So, no coral, only some fish and snails. I noticed that my Calcium is dropping and I'm wondering where it is going with nothing in the tank to use it? This tank has not been seeded with any Coralline that I know of.

I do know that I started wrong with my salt. Using Instant Ocean and not a reef specific salt. However, this does not explain how I have gone from 420 to 360 in a very short time span.

I have ordered an A-B kits to start dosing, but I didn't think I would be doing this so early.

thank you in advance.

 

[Uncle99]

With nothing to use CA, MG, Alk, a weekly water change would keep your parameters on point.
Your absolutely right, way to early to start dosing.

My concern in this case would be low MG, we need to keep a level of 1260-1360 ppm to keep CA and ALK from just coming together.

Test for MG, correct this level only, retest Alk and CA in 24 hours.

If your using the Hanna CA checker, this test is not accurate due to the small sample size and a variance of 50-75ppm can be expected.

Use caution with all hobby tests, sometimes they give false results

Instant Ocean is fine, many use this salt on high demand tanks, they just may need to dose upwards

 

[Jason82]

Thanks. Mg is the only test kit I don't have at this point. should be arriving in the next two days.

I did a water change on Friday. that brought my calcium up to 400, but my test last night (Sunday) only produced a 360.

This may have been the wrong thing to do... I happened to have some Calcium Chloride that I use for making beer. I dissolved some in RO/DI water and brought the calcium up to 440.

 

[Uncle99]

No value in maintaining strict CA/MG/ALK if fish only.
But it won’t hurt.

IO can be a bit inconsistent, but good value for fish only.

If you want to keep these three going on point, just use a better salt.

Red Sea and Tropic Marin make very consistent batches, mix real clean, but a bit more pricey

Assuming your cycle is complete, just make a 10% water change every week and once you have a moderate Stoney coral load, this is where all salts may require dosing as the uptake exceeds the input

 

[mcgyvr]

You may want to read this..
http://reefkeeping.com/issues/2005-07/rhf/index.php
Its fairly "scientificy" though so...

You also may want to do 2 back to back tests to verify its not just inconsistency in your testing.. Often times hobby level kits aren't that repeatable..

I wouldn't overreact just yet either... As the tank is new give it sometime to adjust/stabilize before you start worrying about this kind of stuff..

Don't start overcomplicating with dosing yet.. Only once you have a good amount of corals should dosing be needed..

 

[Jason82]

Good advice, I'm probably being overly enthusiastic because in the past, I've neglected a tank getting to the point where I had so much phosphate and detritus there was no hope of bringing it back. The decision to upgrade to the new tank for a while was weight equally with not having one at all. So, I'm shooting for extreme success with this one.

 

[hkgar]

If your mag is low your calcium is precipitating out with the alk and will be accumulating on your pump impellers.

 

[outssider]

If you are indeed using that much calcium, your alkalinity should be way low. Alkalinity is used much more than calcium.

 

[Jason82]

If your mag is low your calcium is precipitating out with the alk and will be accumulating on your pump impellers.

Mg test kit gets here tomorrow.

 

[Jason82]

If you are indeed using that much calcium, your alkalinity should be way low. Alkalinity is used much more than calcium.

Alkalinity = 8dKH.

 

[outssider]

Alkalinity = 8dKH.

ok....if you are not adding alkalinity and calcium is dropping that much then something is not adding up

 

[Jason82]

Mg = 1500 (On the Salifert test, it never changed color)
Ca2 = 440
KH = 8

 

[Jason82]

performed the Mg test again. It did change to blue this time but still 1500.

 

[hkgar]

performed the Mg test again. It did change to blue this time but still 1500.

Mg = 1500 (On the Salifert test, it never changed color)
Ca2 = 440
KH = 8

Those numbers look fine. How did ca get back to 440?

 

[Jason82]

Those numbers look fine. How did ca get back to 440?

I have some Calcium Chloride that I use for making beer. (I seem to gravitate to hobbies where I lug heavy buckets of liquid around) Mixed It up in some RO/DI and put it in the tank... Problem solved.