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View Full Version : Looking for a way to burn off CO2


KenStanley
06/12/2007, 02:31 PM
I'm using a Coralin 3002 Calcium Reactor and like virtually everyone else the reactor is causing a lower Ph. I have an idea on how I might be able to burn off some of the CO2 but I want to run by some of you guys who are way more knowledgeable than I am.

First I’d like to explain my understanding of why the ph is low because if I am wrong then it would indeed be difficult to correct the problem in the first place. The introduction of CO2 reacts with the media in the reactor to create an acid which dissolves the media which releases the calcium/alk in a balanced form. The Ph of the effluent coming out of my drip reads 6.8 (I realize this may be slightly higher than it should be but for this discussion it should not be of concern. I am still attempting to dial the reactor in.) I keep very detailed alkalinity, calcium, ph and temperature readings. I am also beginning to test for Mg more methodically because I know more Mg will allow a higher Calcium level at the same alkalinity without precipitation. The following are my readings as of this morning. I can provide averages and actual readings over the last few weeks if need be.

Date Time Water Temp Salinity Ph Calcium mequ/L dKh ppm CaCO3
6/12/2007 7:54AM 76.7 1.023 7.93 375 3.830 10.723 191.52

How am I doing so far? Am I understanding the relationships correctly? The problem I perceive having, which judging from the animals in the tank really isn’t a problem at all because I have good polyp extension and healthy, colorful looking coral, is that my Calcium is lower than I would like, the alkalinity is perhaps slightly high and the ph is a little low at times. Ph ranges between 7.93 – 8.13 depending on the time of day. I normally take the test early in the morning before any lights come on and as the day wears on I find the Ph increasing to high end of my Ph range.

I just bought a XP Plus phosphate removal reactor and intend to put Rowaphos and Aquarium Pharmaceuticals Black Magic Super Activated Carbon. The purchase was not to solve the above but for other reasons. I’d like to feed more and thought this might make it possible without the danger of increasing phosphates.

I think the above pretty well describes my situation and this is what I am thinking about the set up. I’m thinking that I will take two hang-on specimen containers measuring 5” x 2.5” x 4” connecting them together at just below the midpoint using a double slip bulkhead fitting. The first container, I’ll call A the second B. The containers will hang-on the inside of my refugium. Container A I will cut down one end so that it will allow refugium water to flow into it and Container B (container B through the bulkhead fitting). In Container B I’ll place the pump that will feed the Phosphate Reactor. I will also let my calcium reactor effluent drip into Container B. The pump will then circulate the water through the phosphate reactor and return the water to the refugium or sump. What I am hoping is that the time effluent spends in Container B and time it takes to circulate through the Phosphate Reactor will allow the CO2 to burn off and allow my Ph to come up.

That’s my plan. What do you think? Am I just spending way to much time worrying about burning off CO2 and thus raising Ph. My targets are as follows Alkalinity 3.25, Calcium 420 and Mg 1300. Perhaps it would just be wiser to run a Kalkwasser drip and be done with it. Any feed back would be greatly appreciated.

Thanks,
Ken

bertoni
06/12/2007, 03:33 PM
CO2 is the usual cause of low tank pH. Unfortunately, it can't be "burned off". Aeration can help a lot, though. Many people are successful with running the output of the Ca reactor into the protein skimmer, for example. What kind of skimmer is on the tank?

KenStanley
06/12/2007, 03:56 PM
Thanks for replying so quickly Jonathan. I appreciate it. I have a SeaLife Systems skimmer rated for 180 gallons. It is located in my sump. If I knew what I know now when I bought it I would have probably gone with Euro-Reef RC Series skimmer. I too have heard of running the drip to the intake of the skimmer pump. The theory being that the oxygen in the bubbles and aeration would bring down the CO2. A friend of mine tried that with very limited success.

What gave me my idea was an article "A Guide to Using Calcium Reactors" by Simon Huntington (http://www.reefkeeping.com/issues/2002-05/sh/feature/index.php) I quote "Another popular technique to remove excess CO2 is to degas the effluent, either by running it through an additional container of calcium carbonate chippings or by dripping the effluent into a small container housing an air stone."

My intention was to also add the air stone to Container B. I guess I should have included that in the original post, huh?

Thanks again for your input. Also I've read a great many of your posts and appreciate the time you have given to help us novices.
Ken

bertoni
06/12/2007, 04:04 PM
You're welcome!

The airstone sounds like it might work. The extra calcium carbonate chamber also can be effective. Let us know how it works!