SPS keep growing but Ca no consumed?

[Elton Wng]

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

[Gary Majchrzak]

so you don't know the numbers?

Originally Posted by Elton Wng

.
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

[Elton Wng]

Originally Posted by Gary Majchrzak

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?

[Gary Majchrzak]

Originally Posted by Elton Wng

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

[Elton Wng]

Originally Posted by Gary Majchrzak

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.

[Gary Majchrzak]

the error is somewhere in the Ca testing...

remember: water changes can replenish calcium

[Elton Wng]

Originally Posted by Gary Majchrzak

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!!!

[akindbro4u]

Lets back up a step. What is system volume and how big of a water chsnge are you doing?

sent from under the sea

[Elton Wng]

Originally Posted by akindbro4u

Lets back up a step. What is system volume and how big of a water chsnge are you doing?

sent from under the sea

My tank is about 700L and 30L water I changed per week.

[kaserpick]

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.

[Elton Wng]

Originally Posted by kaserpick

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?

[kaserpick]

How many SPS corals do you have? Do you have a pic of the entire tank?

[Elton Wng]

Here is the SPS tank I have at home.

IMGL9678A.jpg

Total SPS qty is over 30 different kinds.

[penfold2]

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?

[Elton Wng]

Originally Posted by penfold2

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.

[oscar.millan]

Originally Posted by Gary Majchrzak

yet scleractinian corals are forming new skeleton.
So calcium IS in fact being consumed- the error has to be somewhere else

I concur.

[Elton Wng]

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?

[penfold2]

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?

[wav0718]

http://youtu.be/mI52IyBtjp0

[Constrictor6090]

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!

[Elton Wng]

Originally Posted by wav0718

http://youtu.be/mI52IyBtjp0

Thanks for your info I watch it months ago. And l know it.

[Elton Wng]

Originally Posted by Constrictor6090

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!

Hope your tank is fine. And if you figure out where the problem is please let me know.

[Elton Wng]

Originally Posted by penfold2

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?

At this stage I am planning just keep my tank as it. Let "time" to figure the problem. Maybe just my sps grows not enough so ca just no consumed.

[Acronic]

Forget about why the cal is high. With that much sps you really need to start dosing alk cal and maybe mag. Buy some two part liquid or mix your own. Start by testing sg, alk and cal. Write the numbers on a piece of paper. Now add 40ml of each to the tank. Test the alk and cal again after a couple hours have passed. Write the numbers down. Dont make any additions or changes for 24 hours. Test again. Write the numbers down. Calculate the difference and figure out how much two part was consumed. You now have a base line of what your tank consumes in a 24 hour period and you should be adding that amount daily.

When you dont supplement, corals will take up all the available ions very quickly. Once they are gone, the corals will go "dormant" and not consume cal and alk. I find that when the corals are in this state that "phantom" readings on test kits are common. "phantom" is just a term i use to describe values that are "in perfect range" for corals but do not yeild the desired results of growth and coloration like you describe.

Focus your energy on implementing a solid dosing regime and you will be well on your way to a beautiful reef.

[tmz]

First 50pppm calcium won't hurt anything.

Alk at 6.7 is a little low for my taste,particularly if you want coraline to grow more.If you bake teh sodium bicarbonate (NaHCO3) , you can double it's strength.

When calcium carbonate forms ( coral skeleton, coraline ,a biotic precipitation etc) approximately 50 ppm or 1 dkh of carbonate alkalinity is used for every 20ppm of calcium. That's only 7ppm of calcium consumption for each dkh drop in alk. Often small drops like are lost in testing noise.

What is the pH btw? If it's low some aragonite(calcium carbonate in the tank may be dissolving in some locations and contributing some alk and calcium.