SPS keep growing but Ca no consumed?

Elton Wng

New member
In the past month I use Red Sea test kits to test the water conditions for my SPS tank. I test every 3 days and below are the numbers we got.

I do not dose any CaCl2 or use Calcium reactor, however these numbers no change at all in the past month.
Ca keeps over 500ppm
Mg keeps at 1320~1350ppm(dosing MgCl2)
KH keeps at 6.7~7 (dosing NaHCO3)

But my SPS keep growing but I also found the Coralline algae color is not like pink/purple but just like dark red (As attached picture shown)

I have two questions on this situations.
1. How come does Ca no consume?
2. Does the dark red Coralline algae OK for my tank?

IMGL1176A.jpg

Thanks
 
Last edited:
Ca over 500 = ?

Ca over 500 = ?

so you don't know the numbers?
.
Ca keeps over 500ppm
I have two questions on this situations.
1. How come does Ca no consume?
2. Does the dark red Coralline algae OK for my tank?
Calcium IS being consumed if skeleton is being formed- you just aren't measuring it.
Dark red coralline IME is fairly common on Indonesian liverock. It's ok :)
 
so you don't know the numbers?

Calcium IS being consumed if skeleton is being formed- you just aren't measuring it.
Dark red coralline IME is fairly common on Indonesian liverock. It's ok :)
When I test calcium I use1.05 ml of the test liquid eveytime and the test times over 12 times
Calcium should stay at 520ppm all the time.

By the way, the pink coralline IME is stop growing and the dark red one instead of it. So it still normal?
 
Last edited:
When I test calcium I use1.05 ml of the test liquid eveytime and the test times over 12 times
Calcium should stay at 520ppm all the time.
yet scleractinian corals are forming new skeleton.
So calcium IS in fact being consumed- the error has to be somewhere else :)
 
yet scleractinian corals are forming new skeleton.
So calcium IS in fact being consumed- the error has to be somewhere else :)

Do you have any idea where I should check rotund the problem?

I have been checked many times of my tank but just can not find where is the error point.
 
the error is somewhere in the Ca testing...

remember: water changes can replenish calcium

I know about it, the salt I use is from korallenzuch. The Ca I test is about 320ppm before I change into the tank.

So the Ca should be lower after I change the water. But the number just keep at the it must somewhere gets wrong. I just can not figure out!!!
 
Doing a water change that small will not shift you calcium very much. Over time, I'm sure it would bring it down, but each time the shift would be small. At that high of a level, your test may not be very accurate or precise. I would try another calcium test kit, just to verify accuracy.
 
Doing a water change that small will not shift you calcium very much. Over time, I'm sure it would bring it down, but each time the shift would be small. At that high of a level, your test may not be very accurate or precise. I would try another calcium test kit, just to verify accuracy.

I did it already. I buy Salifert Ca test kit and test at least 3 times, the same answer.

That is why I make this thread to ask any possible missing?
 
Assuming your test kit is accurate and that you are using it properly, you must have dosed something at some point to raise your calcium from 320 to 520. Have you added any other supplements besides the MgCl2 and NaHCO3?
 
supplements

supplements

Assuming your test kit is accurate and that you are using it properly, you must have dosed something at some point to raise your calcium from 320 to 520. Have you added any other supplements besides the MgCl2 and NaHCO3?


Belows are the supplements. No other additional item.

picture.php
 
Some one told me

If use " high KH salt" to change water then the "carbonate ion" will combine with "calcium ion", they will become calcium carbonate and precipitate in the water??

So calcium will become lower, is it right?
 
If KH and/or Ca are high, precipitation can occur, but this typically happens when dosing to very high levels. New saltwater should not have high enough levels to cause precipitation. Plus, precipitation would reduce both KH and Ca, which is not what you are seeing.

If your new saltwater tests at 320ppm Ca as you said earlier, you need to figure out how your tank got to 500+. Unless there is a testing error, that Ca had to come from somewhere. Kalk, tap water, something else?
 
I am taking care of a 360g tank, 620g system and I do not do any waterchanges. I test the water every two days and things can change quickly, I will wait a few days without dosing to see how much calcium is being consumed and I will dose. One day I checked the parameters and then dosed. After a 4 hours I tested again and the calcium level was lower than I had tested before I had dosed. Sometimes I don't even dose and the cal. level will raise. I only top off with RODI water(0 TDS). The tank is filled with a lot of rock, especially marco rock. My theory for the last 4 months is that the rock precipitates into the water, which makes sense, it being a very, very high flow heavy sps tank and that all Marco Rock is is calcium rock. But can it consume calcium? Hopefully this can help and I am so glad I am not the only one having this problem!
 
Back
Top