# DIY Inline CO2 Diffuser



## jasonpatterson (Apr 15, 2011)

Is that a section of clear PVC?


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## johnnyneedlez11 (Sep 6, 2012)

Its actually an old gravel vac I had laying around. 1 1/2" PVC fits perfectly right inside of it.


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## jasb (Apr 25, 2013)

Nice work, i am currently looking as the last failure of mine. I am trying to get everything out of my 5x2x2 planted. I used 4 in pvc, about 24 inch in height, filled with bio balls, heater out the top and co2 plumbed in to the bottom of the reactor. Thought it was a good idea but turns out that the polyurethane based sealant/ adhesive does not stick to plastic. Found that out when i hard a medium sized water leak. Do you have any experience in glueing plastics or do you rely on a gasket of some sort.


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## johnnyneedlez11 (Sep 6, 2012)

Thanks jasp, well I am no expert by any means when it comes to bonding plastics but I can share what has worked for me. As far as the PVC portion of my build goes I used sandpaper to rough up both of the surfaces to be bonded and then used your standard PVC pipe primer and adhesive, both of which can be bought in a pack at Home Depot for 7 bucks and change. 
As for bonding the Gravel vac tube to the PVC I used Hardman fast setting 2 part epoxy which comes in little blister packs, (this stuff I get from work but I have used a Loctite version made for plastic you can get at Lowes or HD in a little syringe thing which seems to work just as well). 
The one thing that ended up leaking on me was the fittings on each end of the diffuser which I tried to seal with liquid tread sealant but did not work out. I ended up removing the sealant and just used the epoxy to seal the threads instead which hasn't leaked yet but time will tell I guess. The big thing to remember is to really rough up and plastic with sand paper and cleaning it good with some alcohol before you try and glue it. Hope that helps.


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## Sluuuder (Feb 7, 2012)

Dang that looks awesome man.


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## johnnyneedlez11 (Sep 6, 2012)

Thanks Sluuder. Here is the like to the build vid that I got the idea and info from. I will also add that because I have a 90 degree elbow on the ends it seems to create just a slight vortex to assist in dissolving the CO2, that and having it on the filter inflow makes it almost perfect with out the need for bio balls or anything. I see no bubbles in the tank and the drop checker is a perfect shade of green.


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## novitt (Nov 15, 2005)

I have had, basically, this same setup for the past 12 years. Works very well. 

Rather than worrying about the drop checker, see if the plants pearl. Plants performing well is the ultimate test. 

Adam


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## Sgtreef (Jun 6, 2004)

Do plants Pearl if using co2?

Mine do not.
one bubble a second.

Jeff


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## Jester946 (Mar 30, 2013)

It looks like You have it setup backwards, water is supposed to enter the top, not the bottom.


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