The Planted Tank Forum banner

DIY Inline CO2 Reactor (REVISED)

4081 Views 18 Replies 6 Participants Last post by  fishykid1
Hey everyone,
As I stated a few days ago, I got my first canister filter at Petsmart. The filter is a Fluval 205 and unfortunately has the ribbed intake and output pipes.
My dilemma for this was how to make a inline reactor on the tank, without having 5 different adapters for it.
Thought this might help anyone who was going to make a DIY reactor, as many have already. I actually went to Home Depot and put this together AS I was there and seeing what was the most simple. Turns out, I looked it up and found out that it was almost like the Rex-Grigg style.
I only spent $17.50 on this DIY project compared to the $100+ on a professional reactor. This reactor is going onto a 20G high, that is heavily planted.

QTY.
1...........1.5" PVC tube
1...........90 degree elbow (1.5")
2...........1.5" to 3/4" slip reducer (w/ threaded 3/4" end)
2...........3/4" to 5/8" threaded elbow (w/ barbed 5/8" end)
2...........1.5" straight slip coupler
2............hose clamps

Steps: (Pretty simple design, just a little know how involved, common sense o_O)

1. cut the PVC pipe to the right length for your tank. I'm making my reactor 14". Drill a small hole 2 inches from the top of the pipe for the C02 line to enter into the chamber.
2. prepare the 2 ends for the 2 slip couplers. then put PVC glue on both ends of the pipe and slide on couplers, make sure they are tight and fully secured.
3. Take the 90 degree (1.5") elbow and prepare the small end of it for attaching it to one end of the coupler.
4. Put the 2 1.5" to 3/4" reducers in place and glue them with PVC glue.
5. Put teflon tape onto the right elbow threads, then screw in tightly.
6. Hook it up and let her run :) (Make sure the reactor is standing upright with the 90 degree 1.5" piece at the bottom. Place the output pipe on the top barb and then place the other tube onto the bottom barb that goes back into the tank for best results)

***Add bioballs or some other media BEFORE you glue the 2 ends on, Otherwise you won't get them in there, and won't diffuse co2 well.***

The ribbed tubing on the output side (where the reactor will be) has to go otherwise too many adapters and a higher chance of a leak. I'm replacing the ribbed output pipe with a 5/8" ID(inner diamter) clear vinyl tube. This will be held in place with a hose clamp.

Pictures will be coming soon!

Thanks,
Fishykid1
See less See more
1 - 19 of 19 Posts
well be waiting for those pictures!!

...cuz I have an engineering degree and couldnt quite visualize it!

but if it works it works!!
if you have a webpage they are hosted on (flickr, webshots, etc....you can use this site too) you can put the web address between
tags
theres a button for it too

...what makes this reactor so much easier than a standard RG style one?
...also, you should have splurged and gotten the standard 2" diameter pvc connectors and pipe...the flow through your reactor will be very high

sadly, I think youll be making this one again...and if you follow the standard procedure...it should cost less than $16 (not a big savings over $17 but it counts)

...Im sorry, but it wont work as well as you had hoped
See less See more
I wasn't saying it was easier. I was just posting what I did, to see if anyone else liked this or wanted to try it. Alot of the DIY builds I see don't have very good pictures/ complicated directions, so I figured that I would try and make them more simple.
I see...makes since
I read simple as in...simple = better
good understanding of the concept/principles to build one on the fly!
You should find non angled hose barbs. Those 90 degree bends slow down blow a great deal.
^not quite

it makes the pump less efficient (more wasted energy in friction)...it does not slow down flow (at the scale were using) if we were using the filter for a tank 100' away, Id consider it but the twists and turns of elbows only equates to about 10' more of filter tubing
I'm still amazed no one uses threaded end caps on these. It was a godsend for me when mine got plugged up with heterotrophic sludge when I had put a filter pad in mine originally (this is a bad idea by the way.).

I put 90 degree elbows on mine to make it fit under my stand. I still have too much water speed. I don't think you'll see much difference in flow rate. I'm sure there is some decrease, but at least in my case it isn't noticeable.

BTW, those fluval hose ends will fit over a 3/4" hose barb (tight). 5/8" tubing will fit over the quick disconnect ends that plug into the pump, but they are a very tight fit. Another trick with the fluval hose is to put a piece of 1/2" or 5/8" tubing on a 1.2" or 5/8" hose fitting and stretch the fluval hose end over it. I find it easier just to replace the fluval hose with smooth pvc tubing wherever there are going to be additional connections. Heating a 5/8" hose in near boiling water will allow you to stretch it over a 3/4" fitting (likewise, it will allow a 1/2" hose to fit on a 5/8" barb).
See less See more
^not quite

it makes the pump less efficient (more wasted energy in friction)...it does not slow down flow (at the scale were using) if we were using the filter for a tank 100' away, Id consider it but the twists and turns of elbows only equates to about 10' more of filter tubing
I always wondered about this. Does any of these 90 degree bends add to the head for the pump?
I don't think pump head is usually a major factor as long as you're pumping to the same level as the water was drawn from.
Okay, have read all of the posts. The reason for the 90 degree elbow at the bottom is because when using a 1.5" pipe, it's not very smart to drill a hole in it for the exit pipe near the bottom. Having a cap on the bottom end with the barb for the output back into the tank would slow down the flow MUCH more than a simple 1.5" elbow piece with a reduction washer down to 3/4" bushing. Right, Wrong?
I'm still amazed no one uses threaded end caps on these. It was a godsend for me when mine got plugged up with heterotrophic sludge when I had put a filter pad in mine originally (this is a bad idea by the way.).

I put 90 degree elbows on mine to make it fit under my stand. I still have too much water speed. I don't think you'll see much difference in flow rate. I'm sure there is some decrease, but at least in my case it isn't noticeable.

BTW, those fluval hose ends will fit over a 3/4" hose barb (tight). 5/8" tubing will fit over the quick disconnect ends that plug into the pump, but they are a very tight fit. Another trick with the fluval hose is to put a piece of 1/2" or 5/8" tubing on a 1.2" or 5/8" hose fitting and stretch the fluval hose end over it. I find it easier just to replace the fluval hose with smooth pvc tubing wherever there are going to be additional connections. Heating a 5/8" hose in near boiling water will allow you to stretch it over a 3/4" fitting (likewise, it will allow a 1/2" hose to fit on a 5/8" barb).
As far as the tubing, I bought the 2 small elbow pieces (w/ barbs) with the threaded end being 3/4" and the barbed end is reduced to 5/8". Does that make sense? Or am I explaining it poorly?
I always wondered about this. Does any of these 90 degree bends add to the head for the pump?
it doesnt add head (major loss)

it adds "equivalent length" of the smaller diameter tubing so a 1/2" (eheim) tubing into a 90degree turn into a sudden expansion (2" reactor) to a sudden contraction to a 90degree turn is about 10' or 1/2" tubing

or...for the equivalent losses it would mean moving your filter 10' away from your tank and running the pipe

the loss of "head" from a reactor would be the same as the friction (minor) from that extra 10' of tubing...

but at our low GPH, velocities and diameters...its negligible


@Fishykid

I think he means using a threaded cap of PVC...so taht you can screw off the entire 2" opening to clean and not a 3/4" hole...Ive just never had a need to clean out my reactor tho

...finally, going from 1.5" (or 2") to 1/2" or 3/4" tubing would SPEED flow up...that pesky conservation of mass thing ;)...
See less See more
Thanks Moneybags, That clears it up. This reactor is going on the outflow pipe, not the inflow. So the only thing that should build up at all is a little bit of algae. Other than that I don't see a reason why I would need to open the reactor up.
2
A little change of plans! Hopefully for the better over all.

So, just an update. I decided to change the design a little bit. It no longer has an elbow piece at the bottom. I have also added a T shaped piece with a 1.5" to 3/4" slip, then a 3/4" to 1/2" threaded reducer. After that I placed a 1/2" to 1/4" brass threaded reduced, then to a 1/8" brass barbed fitting. Sounds complicated but here's a picture of the finished product. The reactor hasn't been installed but will be sitting in the same location in the back as it is in the front. I'm pretty proud of it, no co2 loss other than occasional small spray of bubbles. Turned down co2 to HALF of what it was and am getting more pearling.

See how many bubbles are just flying around the tank? Now I can actually see how many bubbles are actually pearling plants. (EDIT) The burping has stopped completely. The reactor not making any sounds, again NO bubbles are coming out of the output pipe, only nice fresh co2 enriched water :)

Sorry, white balance is majorly off.

Attachments

See less See more
Any thoughts, or advice on this little reactor? It's on a 20G H and is appox. 20" long, with rocks filling about 1/2 of the cavity.
Any thoughts, or advice on this little reactor? It's on a 20G H and is appox. 20" long, with rocks filling about 1/2 of the cavity.
Very similar to mine.

See less See more
Very fancy! I'm loving it. I'm getting absolutely no burping. and My pH is at 6.5. regular aquarium water before co2 starts up is at 7.3 :)

The canister burped because of me doing a cleaning, but no bubbles made it to the output pipe...pretty efficient reactor? I'd say so :)
So, I get home from my youth group and half of the fish are chilling at the top and gasping every few seconds. Solution? OXYGEN!!!! how? Well, If you have a 1/8" T barb and a spare check valve, you can also have aeration through the same reactor. So, in other words; A timer for a air pump and a few check valves/ T splitter. BAM a double purpose reactor :)
1 - 19 of 19 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top