SPS keep growing but Ca no consumed?

[Elton Wng]

http://youtu.be/mI52IyBtjp0

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

 

[Elton Wng]

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]

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.

 

[biodegraded]

Put another way from the last two posts, test for alkalinity, which is our proxy for carbonate, rather than calcium because it's a far more limited reagent in sea water and thus varies more with calcification by what ever means. It would do nothing but good to read Randy Holmes-Farley's articles on this subject in the chemistry forum. It'd be much better than letting time and hope sort things out. Randy recommends 2.5-4.0 meq/l alk.

 

[Elton Wng]

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.

Great! I understand what yuo mean.
Thanks.

 

[Elton Wng]

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.

Yes, I am rising the dosing dhk now. I also feel the dkh is too low for my tank. So after the dkh goes up around 7.5 I will re-start testing the all numbers.