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Question about new RG reactor build

1362 Views 9 Replies 4 Participants Last post by  PamAndJim
I am in the process of building a new RG reactor for my tank and have a question about how to configure the inlet. I have read somewhere that it's best to have the flow coming down from the top like this:

While other have it going in from the side like this one:

My questions is does it matter? In my mind it seems like the second option would be better in terms of flow because I could eliminate the elbow going into the reactor. I realize that the water would still need to make a 90 degree turn, but it seems like it would be less restrictive to do it in a 2" pipe than a 3/4" elbow. But, I can also see how it would be beneficial to have the flow coming down from the top, this using the entire length of the reactor chamber. What are your thoughts and experiences?

BTW, these are not my pics, I just found them on Google.
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The first option would actually be better for dissolving the co2...the water in the reactor wouldn't be able to get to the gas pocket with the second design...which could potentially result in the heater malfunctioning and exploding
Thanks for the input. I'm not actually using a heater in mine. That was just a pic I found online. But, I do think I will go with the top option.
While straight in is better, both of these have a 90 to flow through. One is the el and the other is at the flow so little difference.
I would suggest looking at making a wide swing in the tubing rather than coming to the reactor and then making the change. Think of water flow as traffic flow and you can see that it slows less on a broad curve than on a tight corner? Also I find there are sometimes problems when people mod the design to avoid sticking the tubing through the side as Rex did. The CO2 can travel straight up along the side when it comes in there. The design by Rex puts the CO2 out in the center of the pipe where it meets the flow better. Be assured that there is not a problem with it leaking when done as Rex did it. Drill the hole small and draw the tubing through before sealing it all up to avoid problems with noise from a bubble inside the reactor.
Modding a proven design is one way to create trouble for ourself!
Unfortunately I don't have the room for a wide sweeping turn into the top of the reactor. Also, I will be injecting the co2 as in the original design. My question was solely focused on the flow coming in to the reactor.
Good enough on the elbow, just sometimes we have to work with what we have even when it is not perfect. Just like the highway, we might be better without corners but we still have a bunch.
That should be a good size for a 125. Some depends on what filter or pump you use and how much CO2 you are putting in but I find that size works good for my 125. I run a 2217 Eheim through it and CO2 bubbles to fast to count. Is this a first reactor for you? One point if you have not used one before is to plan an easy way to tilt the reactor if you need to do it to clear air out of the canister after cleaning. May need to and may not but if the canister doesn't fill after the cleaning, try tipping the reactor until all the bubbles stop coming out of the outlet tube. I put a strap on the top tubing going into the reactor and left the bottom free to swivel up when I need to do this. Without the strap ,the reactor tried to turn over and kink the tubing.
This is actually the third reactor I have built. The first was a verges style. I switched to a RG style for space / routing purposes. The one I am using now is made of 4" PVC. I am downsizing because I am barely getting any flow from the output of the filter. I am running the filter (API XL - same as old xp4) output through the reactor, then through my inline heater. I have an fx5 on the other end of the tank, but I don't get enough flow on this end, plus I want to make sure the co2 gets distributed throughout the while tank.
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