DIY CO2 Inline Reactor/Diffuser

[maxwell1295]

I posted this here in the Planted Tanks Forum since it would be of most use to folks with planted tanks. If the mods feel the need to move, I have no problem with that. I just thought it would be more use to the "Plantheads" of AA.

This is pretty much the standard inline PVC reactor. I saw a few variations of this setup online and decided to build one myself. In the process of setting up a pressurized system for my 46G, I realized that the cheapo glass diffuser in there now would not be sufficient. I have always been able to produce CO2 with my DIY setup, but getting it diffused properly has always been a problem. That's where the inline reactor comes into play. I have a Rena XP filter to which this reactor will be attached (on the outlet side).

Step 1: The Parts (all parts were purchased at Lowes)
2" PVC pipe
2"x 2"x 1-1/2" sanitary tee
2" couplings
2" x 3/4" bushing adapter (brass)
1-1/2" x 1/2" bushing adapter (brass)
1/2" x 1/4" female adapter (brass)
1/4" x 1/8" barb fitting (brass)

Stuff


Step 2: Assembly
Assembly was pretty straight forward. I used PVC primer and epoxy on the PVC fittings and teflon tape on the threaded fittings. The PVC pipe was cut into one 8" piece and one 3" piece. I used a sanitary tee since it seems to channel the flow of the CO2 towards the water flow. I figured it would be a bit smother than a standard tee. That was my own added twist. Other than that, everything else is pretty standard.

This unit is pretty much a cross between Rex Grigg's unit that uses 3 tees and the other inline units that use a small airline fitting to inject the CO2.

Exploded view


Assembled view


After deciding that the unit was too long, I took out the 3" piece of pipe and assembled it that way. One thing that I didn't take pics of are the nylon pot scrubbers I put inside the long piece of pipe. Those will aid in breaking up the CO2 bubbles into smaller bubbles that should be more useful to the plants.


Final configuration



I then used some leftover vinyl paint (designed to spray on plastics) to give it a nice, professional look.



Finished product


Now, I haven't been able to test this unit yet so who knows whether it works or not. Now that I have all the parts I need to complete my pressurized setup, I should be able to get this thing up and running in a couple of days. The only thing I need to do is put together a bubble counter so I can keep track of how much CO2 I'm adding. The goal is to keep a steady 35-40ppm.

[rich311k]

Very nice work. I think you will be very pleased with the results.

[Purrbox]

Nice construction job there Maxwell. I like your design decision reguarding removing the extra 3" piece of PVC at the top. While it probably didn't hurt anything it also wouldn't have gained you any perfomance increases and you gained some space by removing it. I'm looking forward to some stats on how it performs for you.

If you haven't decided on a design for your bubble counter yet, I would definately recommend the one that I'm currently using. It's inexpensive, easy to build, and takes up very little space. Here's a link to my thread on the DIY Bubble Counter.

[maxwell1295]

Purrbox, that is a really nice design. I may have to look into that one. In fact, I may have a spare syringe laying around from when I used to give my dog her yearly shots. If not, I can easily pick one up from CVS or Eckerd.

[fish_4_all]

Very nice looking diffusor although I am not sure I would have painted it before testing it.

[wierdkid]

instead of the tee, if you can find a tap the same size as the threads on the brass fitting, use that to tap a hole in the side of the PVC so the CO2 gets injected directly into the water flow (otherwise you might have to make sure the tee points down to ensure the CO2 gets fully diffused into the flow)

[An t-iasg]

Very nice job, Maxwell! It looks nice too!

I moved this thread to the DIY Projects forum. Someone searching for help in building a DIY reactor will probably look in this forum first.

[Electrobes]

I see it's been a while since the last post was done but I was wondering how well this unit worked out for you or anyone else who made one? I like the idea a lot and plan on building one myself, and inline it to a XP3 filter.

Towards the end of the unit (Where the water exits) I was thinking of attaching the auto top-off exit so it wouldn't need to be directly into the tank. Granted there would be a check valve right before it goes to the chamber, but it would be nice to not have any equipment in the tank.

One thing I forgot to ask... where the CO2 enters the reactor... does the reactor not create a siphon that would cause the Yeast and all to get sucked into the water flow?