The Planted Tank Forum banner

The Rex Reactor

115K views 233 replies 91 participants last post by  Morecowwbell 
#1 ·
Ok, since I promised to show how to build a very simple and inexpensive reactor here is the article.



Parts List:

A - 1.75" PVC T
B - 1.75" PVC T with one 1.5" outlet
C - 1.75" PVC pipe about 18" long
D - 3/4" hose barbs
E - 1.5" PVC plug
F - 1.75 " PVC threaded plug with 3/4" thread
G - Same as F
H - 1.75" PVC cap.

Note I picked up these parts in about five minutes at the local Home Depot.

Both T parts can be straight 1.75" with no problem. If they are then E needs to be 1.75"

If you need 1/2" hose barbs then get parts F and G with 1/2" threads.

Part E is simply drilled with a small drill bit and the CO2 feed line is fed though the hole.

Here is the reactor fitted together. Note I have NOT glued anything together. If someone wants to purchase this reactor then contact me via my web site. I can put any size hose barbs you need within reason.

 
See less See more
2
#4 ·
Anywhere between 12-18" long seems to work for me. I like them a bit longer so I always go about 16-20".

Those plastic barbs are over with some of the irrigation stuff.

If anyone has a problem finding barbs contact me though my web site and I can get most any size you need/want.
 
#6 ·
Do you see any media in the picture?

Nope.

There is no media in the reactor. Media in the reactor slows down flow rate. Also it can clog the reactor. I have had this happen before. I took the media out of all my reactors and they work just fine.

I have never built a shorter reactor. I have no doubt they would work just as well.
 
#7 ·
One thing I'd like to note...
as with any slip couplings, you are not limited to the inlet, outlet, and CO2 being in line. You can rotate the T's any direction you want to get the combination that best fits your setup.

An example for my tank would be to have this mounted on the edge of the opening of my stand (Standard corner tank stand with the backs fairly open). The CO2 and inlet would be facing into the stand and the outlet would be on the outside edge pointing directly up the back side of the tank.

Also, Rex, is the outlet end a T to create turbulence? Otherwise, wouldn't a regular elbow work just as well?
 
#8 ·
I just got the parts to make one of these, and I encountered a few simple problems: Lowes and another LHS (Local Hardware Store :wink: ) , both do not have anything with 1.75 inch PVC or CPVC pipes. Not the pipes itself or the other fittings. No big deal, just used 1.5 inch and scaled it down likewise. Also it is extreamly hard to find anything with 5/8 inch barbed fittings. I tried almost everything to make it work, and finally the LHS had one 5/8 inch barb and I used a few adapters to get it to fit right. I still can't figure anything out for the other side.

Anyways my real question is, is there any problem with using PVC cement on the connections?
 
#9 ·
Also, Rex, is the outlet end a T to create turbulence? Otherwise, wouldn't a regular elbow work just as well?
I use a T so I can use a flat plug so it sits level. I would guess it also creates a bit more turbulence.

If you need 5/8" barbed fittings contact me soonest. I will be headed out to a store today that in the past has always carried a good supply of 5/8" fittings. Do you want straight or elbows? What size thread do you want?

Let me know.
 
#10 ·
If you need 5/8" barbed fittings contact me soonest. I will be headed out to a store today that in the past has always carried a good supply of 5/8" fittings. Do you want straight or elbows? What size thread do you want?
I actually just contacted someone at my LHS and they are ordering the piece for Thursday. But thanks for the great offer. BTW, do you know about the PVC cement? (See other post)

Anyways my real question is, is there any problem with using PVC cement on the connections?
 
#12 ·
Nice writeup Rex, thanks once again for a straight forward, simplisitic, NO BS design and documentation.

I was planning on building a similar one today from home depot/lowes parts before reading this thread, and now it looks like it'll be even easier than I thought. :)

Robert
 
#16 ·
Fosty said:
Sorry for all the questions, but just one more and I'll be done for good: Is the PVC Cement nessacary, or can it be alright and stay leak-free without it?

How else would you hold the PVC together? Duct tape?

PVC is designed to work with PVC cement. All plumbing in houses is done that way. Custom plumbing on larger tanks and fish rooms is done with PVC pipe and PVC cement.

Just give it a couple of days to cure and then flush it out and you will be fine.
 
#18 ·
Well I just finished building my first DIY reactor based on this thread. This was very easy and maybe cost 15$ in materials. I was able to find everything at home depot. The only compromise that I had to make was to use 1.5" PVC instead of 1.75" or 2" for lack of available fittings.

The total length of the reactor is about 24" and is attached to a 150 gallon tank, which brings me to one question: is this reactor big enough to handle this size of tank? From what I've read around here, it should be fine but I'd like a definitive answer from someone :)

Also I suggest that this thread deserves a sticky for us n00bs that ask the same questions over and over!

Thanks!
Robert
 
#19 ·
Nice simple plan, thank you Rex. :proud:

wob said:
The only compromise that I had to make was to use 1.5" PVC instead of 1.75" or 2" for lack of available fittings.
Depending on the flow of your filter it might push bubbles out on the other end with only 1.5" diameter. It might be okay with a monster two feet reactor. :icon_bigg You will find out.

wob said:
The total length of the reactor is about 24" and is attached to a 150 gallon tank, which brings me to one question: is this reactor big enough to handle this size of tank? From what I've read around here, it should be fine but I'd like a definitive answer from someone :)
If the bubbles stay within the reactor, a inline reactor can handle a 150 gal tank easily. Only thing to worry about is the distribution within the tank. If you have good current going throughout the tank it shouldn't be a problem.
 
#20 ·
Wasserpest said:
Nice simple plan, thank you Rex. :proud:



Depending on the flow of your filter it might push bubbles out on the other end with only 1.5" diameter. It might be okay with a monster two feet reactor. :icon_bigg You will find out.



If the bubbles stay within the reactor, a inline reactor can handle a 150 gal tank easily. Only thing to worry about is the distribution within the tank. If you have good current going throughout the tank it shouldn't be a problem.

Well the pump that is driving the filteration system (raindbow lifeguard mechanical and heater module) is a quiet one 3000 rated 780gph @ 0ft of head, ~620gph @ 4ft, so the flow is pretty strong out of the spraybars, so I'm not too worried about good flow in the tank. I guess we shall soon see if it's so strong it pushes the bubbles out the bottom :)

Thanks for the info, I'll post my findings later this week when I get my co2 tank filled.

Robert
 
#21 ·
Has anybody experimented with the depth of the CO2 inlet tube in the tee? In other words, do the bubbles accumulate at the top of the tee to form a reservoir of the gas or do you give the bubble a wild ride by injecting it directly into the stream?
 
#22 ·
I assembled one of these today cost me about 20 dollars for everything(cement included). I went with 2" pvc since it was the only size I could find everything in heh. I do have a couple questions though on the c02 inlet what size drill bit should I use for that and should I use any kind of sealant around it?

Thanks btw rex for an easy to assemble reactor!

Oh and I was able to get everything at Lowes my Home Depot didn't have much of anything needed...
 
#23 ·
For normal air line tubing I have found that an 11/64th drill bit works fine. You want a drill bit that is about two bit sizes smaller than the OD of the tubing. Then you cut the tubing at an angle and pull it though with pliers. Start with a small hole and drill it out if you need to. You want the smallest possible size hole you can pull the tubing through.

There is no need for any sealant.
 
#24 ·
g8wayg8r said:
Has anybody experimented with the depth of the CO2 inlet tube in the tee? In other words, do the bubbles accumulate at the top of the tee to form a reservoir of the gas or do you give the bubble a wild ride by injecting it directly into the stream?

I always pull enough tubing into the T to bring the tubing into the middle of the pipe.
 
#25 ·
Mine is very similar to Rex's...except I use 2 in diameter pvc...and used a 1/2 inch drill bit to get the hose barb input into the side of the reactor...used a 1/4 bit to get the brass 1/8 co2 barb into the side too.

The original reactor was made of just the clear pvc...then I realized it was too short for the power of the 2026...extended it by at least a foot with the regular pipe.

A much more efficient reactor than the top-down versions...I think the length itself makes it more efficient. It will drive my pH from 7.1 to 6.4 with 10-12 bubbles per MINUTE.

As far as a pocket of gas forming at the top...there has to be an initial buildup in order for the turbulence to actually break down the gas..but its minimal (not a 2-3 inch gap of air/gas).

 
#26 ·
Rex,
Have you ever used a brass fitting instead of drilling a hole in the PVC plug? I built my reactor a while back using 1.5" PVC and instead using a plug and having to worry about the possiblity of leaking, I used a 1.5" to 1/2" PVC reducing plug and screwed in a 1/2" NPT to 1/8" brass compression fitting.

I know this does not allow for you to put tubing up into the reactor, but I never had an issue with this because I used Bio Balls in the reactor.
 
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