PDA

View Full Version : aragonite ?


fullmonti
10/14/2009, 09:07 AM
I saw on another forum that aragonite could be used to reduce excess CO2 from a calcium reactor so you could use less or no kalkwasser to keep ph up.

Is this true?
If so how much & how is it used?
Are there any undesirable side effects from using it?
Where is good place to get it?

lordofthereef
10/14/2009, 09:11 AM
I am not sure what exactly you are asking. Are you asking if aragonite can be used as calcium reactor media? I thought that was what people generally used.

Randy Holmes-Farley
10/14/2009, 09:21 AM
Yes, it is the normal media that is used. Some reactors add a second chamber, also filled with aragonite like the first chamber, to more effectively use the CO2 that is added, so the pH reducing effect can be minimized somewhat, but CaCO3/CO2 reactors necessarily must add excess CO2 to the aqaurium and may contribute to lower pH.

FWIW, many people find their home air CO2 level will drive pH down regardless of whether they use a CaCO3/CO2 reactor or not.

fullmonti
10/14/2009, 09:44 AM
OK that is exactly the question/issue I have. I would like to not use or use less kalk to keep ph up. I'm not familiar with aragonite or second chamber application. I'm also trying to decide where to drill hole in wall to bring air line from out side to feed skimmer.

This question started for me when I had a algae issue & nitrate&phosphate both at 0, & every thing else seemed to check out fine, I was using zeo system & one of the guys on zeo website said some algae can consume kalk build up on rocks ect. I'm still not sure if this is true or not but it's always nice to not have to dose some thing any way isn't it?

tmz
10/14/2009, 09:56 AM
Algae won't consume kalk precipitant as far as I know. Aragonite is the media you are using in your calcium reactor now. A second chamber application is just a second tube filled with extra media that you let the calcium reactor effluent pass through before getting to the sump/tank.I use both kalk and a calcium reactor. More kalk than calcium reactor. If I chose one .FWIW, I'd choose the kalk.

redfishsc
10/14/2009, 10:36 AM
Could one not take the effluent from the reactor and allow it to drip into/near the intake for their skimmer? Seems like this would drive off a lot of excess CO2, or is there fear that the effluent will be skimmed out as well, or that the low pH would reduce the skimmer efficiency?

kaskiles
10/14/2009, 10:59 AM
guys on zeo website said some algae can consume kalk build up on rocks ect.

Coralline algae will consume Calcium and Alkalinity, which Kalk dosing provides. I don't know if it will consume precipitated calcium carbonate that has settled out on stuff in the tank... The Purple Up people think that it will though...

Boomer
10/14/2009, 11:01 AM
No, that would work also and many do that but a second chamber is a better way to go as you are not only removing CO2 but adding more Alk.

Randy Holmes-Farley
10/14/2009, 11:18 AM
The Purple Up people think that it will though...

I'm not sure they believe it themselves, but it does appear to be what they claim when the product is carefully considered. I certainly do not believe that coralline can dissolve particulate CaCO3 from the water column and then use that calcium or alkalinity preferentially to what calcium and alkalinity is already surrounding them in the water.

Randy Holmes-Farley
10/14/2009, 11:22 AM
'm still not sure if this is true or not but it's always nice to not have to dose some thing any way isn't it?

Maybe. You have to top off for evaporation anyway, and using lime may have other benefits. It is basically all I use. :

Moreover, the question remains whether a second chamber is going to solve a low pH problem. If you have excess home air CO2, it will not help at all. So you may end up adding the second chamber and not achieving your goal.


One way to know in advance is to take out a cup of tank water and aerate it for an hour and remeasure the pH. If it stays low or drops, then the problem is the air, not the reactor. I discuss that here:

Low pH: Causes and Cures
http://reefkeeping.com/issues/2004-09/rhf/index.htm

Randy Holmes-Farley
10/14/2009, 11:26 AM
I was using zeo system & one of the guys on zeo website said some algae can consume kalk build up on rocks ect.

Some of the zeo folks seem to have convinced themselves that limewater precipitates phosphate and that somehow this is a problem, perhaps by algae on the rocks dissolving the phosphate back out of the precipitate.

I’ve never seen any evidence of this, and I'm not sure how having phosphate in precipitated calcium carbonate could be worse than having phosphate in the water column itself, but that belief of theirs is perhaps the basis for the comment that you saw.

fullmonti
10/14/2009, 05:10 PM
Bunch of good info

It will take a little while to digest, research, & implement some of this. thanks

Mike O'Brien
10/14/2009, 07:03 PM
How much phosphate could be incorporated considering it's concentration compared to the concentration of Magnesium and other things that can foul crystal growth. I can't see it being that much.

Boomer
10/14/2009, 09:32 PM
Randy

The only algae that can do that is cyanobacteria and they have to do it extracellularly.

Where did that Kalk quote come from. Kalk precip on rock in tank ? How is that going to happen it is to soluble. Or are those Zeo guys lost again :)

Moreover, the question remains whether a second chamber is going to solve a low pH problem. If you have excess home air CO2, it will not help at all.

The second chamber, which do work well, is only to increase the effleunt CR pH some so the tank pH is a tad higher than without it. By no means is it to help a tank with low pH from high room air CO2. I also think their having phosphate in precipitated calcium carbonate is gibberish in regards casing PO4 issue in a tank. It still that "can of food"