The Rex Reactor

[Rex Grigg]

Originally Posted by Fosty

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.

[Matak]

Bookmarked!

Thanks Rex, this will replace the cheezy Boyu (read: glorified airstone) that requires 1 bps at 13° KH in a 29g tank to make 25 ppm CO2

[wob]

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

[Wasserpest]

Nice simple plan, thank you Rex.

Originally Posted by wob

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. You will find out.

Originally Posted by wob

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.

[wob]

Originally Posted by Wasserpest

Nice simple plan, thank you Rex.



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. 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

[g8wayg8r]

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?

[shady3210]

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...

[Rex Grigg]

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.

[Rex Grigg]

Originally Posted by g8wayg8r

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.

[Georgiadawgger]

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).

[Thooshe]

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.

[zelmo]

Originally Posted by Rex Grigg

There is no need for any sealant.

Over time, doesn't airline tubing get hard? (Maybe I'm just showing my age!) If so, won't this design leak?

I currently run an airline tube to the inlet strainer on a Magnum 350. I can see how many bubbles are released and it seems to work fine with regard to not creating problems with the filter. I thought it was pretty effecient also - I had good readings on PH with only a bubble every other second. Then I found out my PH kit was WAY off. Actual 7.3 read as 6.6. I am now trying to figure out the correct bubble rate but it is going to be alot higher than before.

So, can I build a reactor similar to this, eliminate the tube in the reactor, and keep it on the intake side of the Magnum? Seems like the bubbles would get sucked down to the reactor just like they go into the canister now.

[tazcrash69]

Originally Posted by zelmo

Over time, doesn't airline tubing get hard? (Maybe I'm just showing my age!) If so, won't this design leak?

I currently run an airline tube to the inlet strainer on a Magnum 350. I can see how many bubbles are released and it seems to work fine with regard to not creating problems with the filter. I thought it was pretty effecient also - I had good readings on PH with only a bubble every other second. Then I found out my PH kit was WAY off. Actual 7.3 read as 6.6. I am now trying to figure out the correct bubble rate but it is going to be alot higher than before.

So, can I build a reactor similar to this, eliminate the tube in the reactor, and keep it on the intake side of the Magnum? Seems like the bubbles would get sucked down to the reactor just like they go into the canister now.

You want to put the reactor on the outflow of your can.

[zelmo]

Originally Posted by tazcrash69

You want to put the reactor on the outflow of your can.

While that is certainly true of many canisters, the Magnum is a pull type. The way I have it now the bubbles go right down to the canister. With the impeller at the bottom there aren't any problems with air locks. I may find out differently as I get dialed in (I just found out the test kit was bad last night) but my only concern right now is efficiency. The bubble rates others are reporting are far lower than what I am getting.

[Georgiadawgger]

Originally Posted by zelmo

While that is certainly true of many canisters, the Magnum is a pull type. The way I have it now the bubbles go right down to the canister. With the impeller at the bottom there aren't any problems with air locks. I may find out differently as I get dialed in (I just found out the test kit was bad last night) but my only concern right now is efficiency. The bubble rates others are reporting are far lower than what I am getting.

I'm not sure if you understood...there should be an output to the Magnum that returns water back to the aquarium...that is the line that gets plumbed into the reactor (to churn the co2 bubbles).