Co2 De-fusser A.K.A Co2 scrubber

[hnguyen]

For those of you that's been having trouble with their pH kinda low, I may just have the answers to your prayers. I've just set my DIY Co2 De-fusser A.K.A Co2 scrubber. Its pretty much the same concept as a rebreather. Now I know that you can buy this online and save yourself the trouble but I think those things run around 50 to 60 bucks a pop and the refills for them are like 20 to 30 bucks. So a DIY would save you much more money and it still works the same. I've had mines up for about 2 days now with my chamber filled just under half way with media and it brought my pH up about .20 which leaves my very low pH now at 8.0 during the day and about 7.95 give or take in the evening.

Ok now things you will need before you get started. (I'm listing the things I used to make mine's, If you have somethings that will work the same way than go at it.

1) few pieces of acrylic. (size will depend on how big you want your reactor)
2) air line tubing that will fit into your skimmer's air intake.
3) media bag
4) soda lime media. (rebreather)
5) acrylic joiner
6) elbow tube connector ( lol I dunno the name of it but its the piece your going to connect your airline to)

Ok, first off decide on how big you want your reactor. I think a 4"x4"x10" high would be perfect, Mines was a little bigger because that was just acrylic I had laying around. After you have cut out your acrylic pieces to the size you want. make sure to cut a piece for the bottom plate as well. Gather all your material and join with together to get a box with your acrylic joiner. I also cut out 2 piece to the inside dimensions of my box to act as a led and a strainer. To hold my led in place I cut up small little strips of acrylic to the width of the inside of my box and I joined it just about a 1/4" under the top rim so when I sit my led on the box it won't fall in.

Notice how I have a gap on the bottom of my chamber. I did that so there would be an air pocket in there as to not restrict the air flow into your skimmer thus it wouldn't affect the performance of your skimmer. The way I did that was I just cut up some 3/4" thick acrylic to be about 1/2" wide and 1" long. I cut 4 of them and joined them standing up so you get the 1" height. Now take the other piece of acrylic that you cut to act as a strainer and drill a bunch of 1/8" hole into them so air can pass through but at the same time keep the media out.

Now drill a hole on the side of your reactor towards the bottom. I drilled mines right in the middle of the air pocket I made so that would be about half an inch from the bottom. Than take your elbow connector and stick it in the hole you just drilled. You can use caulk to seal it or just regular PVC joiner like I did. (just to make it air tight) After that you will need to drill a hole on top of your led, about 1/4" will do good, If not 3/8" will be perfect if you have a bit that size.

Now its time to hook up your air-line tube to your reactor and into the air intake of your skimmer. take your led and snap it into place and check your skimmer to make sure that its still running properly. If it doesn't than that means the hole you drilled on your led isn't big enough. ( But I don't think that will happen since my hole is only 3/8")

After the test checks out ok then its time to add the media. The more you use the more Co2 it will absorb. I put about a Lb. of media into my reactor and it seems to do find. I'd add more but this junk isn't cheap! Now your done! Just leave it and forget it! After about 12 hours or so you should notice a difference in your system. For me I set-up my system during the day and I notice it started to work because my pH didn't drop in the evening. it stayed at 7.9 and than during the next day it went up to 8.0. :yay:

The whole reactor didn't cost me a thing because my LFS gave me the acrylic since it was just scrap laying around and the soda lime was given to me by a friend to try out. But if you were to go out and buy all this material, I don't think it would cost you more than $20 minus the soda lime. You can get your soda lime online or locally as well. As to where you can get it I'm not sure of. I still have to look them up so that I can go get refills as well. I hear that a 5 gallon bucket of soda lime will run you around 70 to 90 bucks depending on where you get it. But if you only fill a Lb at a time than it should last you maybe 6 months. You'll know when you have to replace your soda lime because it will turn from white to blue/purple color. Once that happens you MUST remove the old soda lime and refill with new ones or will it will release the Co2 back into your system if you have enough airflow through your chamber. This is also the reason why I use acrylic, so that I can see through it to know when I need to replace the media.

So thats it!! with that in place you should see a good difference in your pH within the next day after set-up. If you guys have questions or comments feel free to share! Enjoy and good luck with your build

 

[jef4y]

I have been doing some reading on this lately as well, and am interested in trying it out. Where did you pick up your soda lime? Interested in splitting a bucket?

 

[hnguyen]

SURE!! I'm always interested in splitting an order! With the amount that comes in a bucket. I'm afraid it will go bad before I get to it, so a split would be great! I can also help you make the reactor as well if you want. My LFS is pretty cool about giving me some left over scrap and he's also got the tools to make it as well. As for the soda lime, the guy that gave it to me said he got it at some place up in Duluth. I have to get with him for the name of the place.

 

[jef4y]

My pH was running as low as 7.68 at night and peaking in the low 7.8's. I started minimal kalk dosing as I have a calcium reactor and don't need the additional calcium but need to absorb CO2. That brought be into the 7.75-7.9 range, but recently I've been able to keep a window open 24x7 which has had me in the low 8's.

Realistically I cannot keep a window open 24x7x365 and I have no way of piping in fresh air, so this could be a realistic addition that could help keep me above 7.8 in the winter and dead heat of summer.

It's cheap enough and benign enough to give it a try. No moving parts or wet parts makes it almost a no-brainer.

 

[hnguyen]

I agree with you completely dawgdude, but I wouldn't consider this chasing numbers. Its kind of like a pH buffer that's always buffing. Theres nothing in there to help raise your pH. This is intended to remove the Co2 that your skimmer sucks in thus helping your pH raise by just a little. My pH before was at 7.9 and I was fine with it since it only goes down to 7.8 in the evening. Now with this It stays at 8.0 during the day and it only drops to about 7.95 in the evening. If anything I would call this a pH stablizer!

dawgdude;565119 wrote: If your ph isn't below 7.7 consistently I would not mess with this. Playin with ph will come back to bit you if you chase a number. FYI my reef stays at about 7.9 and has for years.

 

[hnguyen]

YUP!! So as I stated before. This has proven to work for my tank so if your still interested we can split a bucket of this stuff. If you want to make this even cheaper you can go with a PVC tube but you'll just have to open it up every other day to make sure that the media is still good. but with the clear acrylic you can just look at it as you pass by.

JeF4y;565128 wrote: My pH was running as low as 7.68 at night and peaking in the low 7.8's. I started minimal kalk dosing as I have a calcium reactor and don't need the additional calcium but need to absorb CO2. That brought be into the 7.75-7.9 range, but recently I've been able to keep a window open 24x7 which has had me in the low 8's.

Realistically I cannot keep a window open 24x7x365 and I have no way of piping in fresh air, so this could be a realistic addition that could help keep me above 7.8 in the winter and dead heat of summer.

It's cheap enough and benign enough to give it a try. No moving parts or wet parts makes it almost a no-brainer.

 

[acroholic]

dawgdude;565119 wrote: If your ph isn't below 7.7 consistently I would not mess with this. Playin with ph will come back to bit you if you chase a number. FYI my reef stays at about 7.9 and has for years.

I have always tried DIY projects so all power to you. But, I also agree with Charlie that in a tank that has normal range calcium, alkalinity and magnesium the pH of the tank is not that important.

Make sure you test regularly if you do not already.

Many folks also just run an air line to the outside for their skimmer intake and have the resulting pH increase like you did, but they are not paying for the media. Not practical for me because of the location of my equipment. There is less CO2 in outside air than in our closed up houses.

What you are going to need to look at eventually, Hnugyen, is what is going to happen to your tank pH when you bring your calcium reactor online? Effluent from calcium reactors enters the tank water at pH as low as 6.3 depending on your controller setpoint.

You have all the earmarks of a fledgling gagdet freak, like me, so you will also eventually research and/or try a sulfur denitrator for nitrate removal. Effluent from sulfur denitrators enters the tank water at an even lower pH that it does from calcium reactors. I have two of them, one on each of my reef systems. So pH suppression is a concern for me because I have a calcium reactor and sulfur denitrator on each of my systems.

For me, the solution to pH issues is a Nilsen Stirrer, which is a kalkwasser reactor. Kalkwasser adds calcium to the tank water, raises tank water pH (comes out at pH 12-13), and indirectly contributes to raising alkalinity in the tank, and is supposed to aid in binding phosphates, although how much phosphates are bound is questionable. The above statements are based on what I have researched on the web, but they make sense. The kalkwasser neutralizes acids in the DT water that would otherwise use up tank alkalinity in the biological processes of the tank.

You might want to look at using the money for the soda lime you will spend over a year and investigate earmarking that for the purchase of a Kalkwasser reactor (Nilsen Stirrer). Used ones are on here regularly for $100-$150.

I have an MRC Nilsen that keep my pH 8.1-8.3 .All I do is put 2 cups of kalk powder in it every 2-3 weeks. Calcium Hydroxide is a lot cheaper than soda lime

 

[hnguyen]

Great info acroholic! I've always wonder what a kalkwasser reactor was used for and now I know. Since you put it that way I may look into getting one of those as well. FYI I already have a calcium reactor running right now. I'm using a coralife reactor and I just ordered a GEO 618 to replace the coralife. So as far as calculating the effluent from the calcium reactor goes, I've already got that covered. I still want to learn more about a kalkwasser reactor so if you know an article that talks about how it works and what it does, please send it my way. You also said that the kalkwasser will raise your tanks alk and calcium? so will that be an overkill if I'm running a calcium reactor along with the kalkwasser reactor? or does it not have an affect on your cal. alk and mag levels?

 

[acroholic]

Hnguyen;565153 wrote: Great info acroholic! I've always wonder what a kalkwasser reactor was used for and now I know. Since you put it that way I may look into getting one of those as well. FYI I already have a calcium reactor running right now. I'm using a coralife reactor and I just ordered a GEO 618 to replace the coralife. So as far as calculating the effluent from the calcium reactor goes, I've already got that covered. I still want to learn more about a kalkwasser reactor so if you know an article that talks about how it works and what it does, please send it my way. You also said that the kalkwasser will raise your tanks alk and calcium? so will that be an overkill if I'm running a calcium reactor along with the kalkwasser reactor? or does it not have an affect on your cal. alk and mag levels?

Whether you need to dose Kalk depends on what you are growing. I have a 300 gallon tank with some dinner plate size acropora colonies in them and many other sandwich plate size ones as well. My tank has a pretty high calcium demand. If your tank is mostly sofites or other corals that do not lay down a skeleton, then your calcium demand will be a lot less than an SPS tank, and your GEO might well do the job without need for other calcium sources.

Here is a pretty good article on Alkalinity in Marine Systems by Anthony Calfo:

 

[hnguyen]

cool! Thanks again for the info Acroholic. As for my tank goes, I have a little bit of everything in there. but I'm starting to load it up with mainly just SPS so I know my calcium demand in my tank will increase within the next couple of months. But I'm only running a 120g so I agree with you that the GEO will get the job done just fine.

As for my Co2 scrubber, I'm running that because I can't run a 20ft air tube to the outside of my house nor can I leave a window open 24/7 since its either freezing cold are burning hot here in atlanta with a nice breeze every blue moon. So by running the Co2 scrubber I can keep my pH in check. It doesn't raise my pH or nothing, It just removes the Co2 that my skimmer intakes thus keeping my pH stable. Otherwise I my pH would swing about .15 to .2ppm during the evening and daytime since I have 6 members in my family, thats a lot of hot air :lol2:

If theres someone else out there that will do the same as this for cheaper, please let me know.

 

[hnguyen]

Any idea what happen to my pictures?

 

[jef4y]

If they were uploaded to the site they may have been purged.

 

[hnguyen]

I was afraid of that. I don't have back ups of the pictures either. Dang it!

 

[bluespot]

I currently have a CO2 "scrubber" that I have been using for about 4 months. It isn't anything special. Instead of building a chamber, I merely used an empty 1L matrix bottle. I drlled a ton of holes in the bottom and about 2" up the side. I cut 2 sponge/foam filter pads into circles. One in the bottom to keep media from falling out of the holes and one between the media and the lid. I drilled a hole in the lid and twisted a brass fitting into it and ran a piece of tubing from it to the nipple on top of the skimmer air inlet. I have it sitting on top of my sump. Cost about $2 and took maybe 10 minutes to make. Holds about a lb of media and lasts about 3 weeks.

I get a pH increase of .2-.3. I havent ordered a bucket yet but airgas carries them. I am still using the 2 bags (3lb each for $7 a bag at medvet) i started with. I haven't noticed any detrimental effect to the skimmer. You can see the media changing to purple as it is used up very easily inside the bottle.