Degassing calcium reactor effluent

[discuspro]

When I was in laboratory I learned the term "degassing," which simply meant removing the gas from the liquid as much as possible. With a normal calcium reactor there is effluent, or liquid coming from the reactor that has dissolved calcium and other stuff. In the liquid there is also carbon dioxide and I know that because the desired pH of effluent is normally around 6.7.

So my question is, what are people doing to "degas" or lower the carbon dioxide level from the effluent so that it does not chronically lower the pH of the entire system. I was reading from my Pinpoint pH controller manual to use an air stone in a cup that the effluent runs into, but I was wondering if there is a cooler, better method?

[akm]

I think there are only two ways in which people usually do this, having a second chamber is a good way but it's also more expensive. You can also drip the effluent into a cup and then have it drain out of there. I don't see what would be so hot about a little air pump, it probably would raise the temp at all.

[SaltyJim]

I think he meant "cooler" as in cleaner, more streamlined, cutting-edge, etc. Not cooler like the temp. I could be wrong though.

But, tagging along to see if there are some other ways.

[discuspro]

Yeah, cool like hip and snazzy. I was wondering if there was some kind of effluent chamber or something that someone sells that does degassing to the effluent very nicely, with the idea of bubbling air through to equalize the co2 and oxygen concentrations.

By the way, I've got the Procal Calcium Reactor, which is one of the biggest calcium reactors I've seen and I've got it running on my little 37gal system. The reactor is dual chambered, and I haven't had any problems with lowering the pH yet because I've hardly ran the reactor yet since the first time I turned it on it shot the alk to 20dkh or so and I'm letting the alk rest, right now we are at around 11dkh.

[hobogato]

i built a small acrylic chamber inside my sump into which the effluent drips and the pH probe for my controller rests. it then drips out into an area of the sump where water is falling over a baffle, lots of bubbles and surface agitation. i am running a dual chamber reactor where the pH of the effluent returning to the tank is around 6.9, which maintains the pH in the first chamber at 6.6.

[discuspro]

Happen to have pics of that chamber you've made? Also, how are you measuring the pH in your seperate reactor chambers?

[hobogato]

it is just a little acrylic box that is glued into the side of the sump with a drain hole and an elbow fitting in the hole to direct the water out into the current of the sump. no pics, i will try today when i get home from work.

i measured them as i was dialing in the reactor. my reactor is one i made, and i designed it so i could disconnect the two chambers and measure the effluent of the first chamber very easily. about three days of adjustment and running showed me that if my overall effluent was 6.9 then the effluent of my first (recirculating) chamber was 6.6 which is what i wanted for the ARM media. the second chamber is not recirculing, effluent from the first chamber feeds into the bottom of the second and then the effluent to the tank comes from the top of the second chamber.

[safeuerwehr]

I have my effluent draining into the intake side of my skimmer which everyone knows produces lots of bubbles and aggitation....have not had any problems with my display ph constant 8.1-8.3.

Alfred

[ackelley]

yah that would work well another option would be to maximize the surface aria (shallow wide aria that the H2O can slowly migrate across) this will help with P* and temp. CO2 should have a larger P* than H20, i mean it has a lot lower Tc than H2O so i would think it would. I would still go with the skimmer though a lot simpler and will work better. If you can find a way to lower the density of the water then that will work well also (thats what the skimmer does to an extent in this situation) and find a cool way of doing it. Then i want to see the pictures so i can use it on one of my school projects. :} ascetics i lack a lot

[matt]

Lots of people will drip the effluent into the skimmer input, where it gets subjected to lots of air before entering the overall system; aquaC describes this as "blowing off" the excess CO2 but that's not really what happens at all. Reactor effluent does not have "bubbles" of CO2, it's got dissolved CO2 which is carbonic acid. The only way to get that out is to neutralize the acid. Unfortunately, Ca and Carbonate solubilty in water is ph based, so as you raise the effluent ph you also limit the amount of Ca and Carbonate ions possible in the effluent. The extra chamber that Ace is talking about allows the acidic effluent to dissolve a little more calcium carbonate and consequently get a little neutralized, raising it's ph while keeping the effluent fully saturated with calcium and carbonate ions.

By far the most effective way of preventing a ph drop in a tank fed by a calcium reactor is to drip KW. The hydroxide reacts with dissolved CO2 in water (meaning carbonic acid, which is what the calcium reactor effluent has alot of) to produce carbonate ions (okay, mostly bicarbonate at normal tank ph in case Gary raises a stink) and the more acid there is, the more carbonate you'll get out of the KW. Running KW and a calcium reactor really helps each do the most for your tank.

I have found that keeping calcium reactor effluent very low in ph does not lower the tank ph nearly as much as running a slightly higher effluent ph but having to increase the amount dosed. If you have a big reactor and a small tank, you can probably run a VERY slow drip of reactor effluent at 6.5-6.7, depending on your media type, without dropping your ph. The low ph effluent is very high in alkalinity and you'll find that this almost immediately takes care of any ph issues. The trouble is finding a valve for the reactor output that allows you to reliably control a drop or two every few seconds. Ideal would be, guess what, my favorite piece of aquarium equipment, a medical dosing pump. You could also try a dwyer flow meter, which also works GREAT for controlling the CO2 flow into a reactor.

[sharkboy]

Can someone explain the term "effluent"? It is used as in "reactor effluent, pH effluent"; what exactly makes up the effluent? I am looking into getting my first Ca reactor/ Kalk reactor combo and want to get input on what is the most user friendly/safest and effective. I have read that a dual chamber fluidized reactor is most efficient. Don't know exactly a whole lot about this. Seems rather technical and not user friendly.

[Texreefer]

Effluent is basically a fancy word for the low PH calcium laden water that comes out of the reactor

[matt]

The dual chamber reactors typically have CO2 injected water circulating through only the first tube; the output of that tube (AKA effluent, as Texreefer explained perfectly)then runs passively through a "static" tube of calcium carbonate media, with no circulation pump or CO2 injection. The extra contact with the media tends to raise the ph of the effluent before it exits that tube into your tank.

But, if you're also going to run a KW reactor, you don't have to worry about it. As I said in my earlier post, any carbonic acid in the reactor effluent will quickly react with the KW in the tank; in fact KW needs to react with CO2 (carbonic acid) in tank water to produce carbonate ions from the hydroxide. So, I would suggest if you're running both a calcium reactor and KW, just use a single chamber calcium reactor.

[sharkboy]

Any suggestions on a Calcium reactor and Kalk reactor for a 215 that will contain sps/lps?

[BIGBIRD123]

I would suggest you have Ace build them for you.. Here's the ones that He and I built for my tank ( and future up-grade)....
http://i76.photobucket.com/albums/j20/onebrickstrait/stevereactors.jpg


HTH, I am just now getting these online. I can't wait to see the results. These will run a 600g system (or the Dallas Aquarium) LOL!

Steve