Remote Reactors Return Line (Manifold?)

[kylewest]

For a number of reasons (space, ease of access, ease of maintenance, etc.) I want to move 3 media reactors to closet about 10 feet away from the tank. Getting water to the reactors is easy: I'll run hard PVC through the wall terminating in a manifold that feeds the reactors.

 

How do I get the water back to the tank? My first thought was another manifold but I'm worried that the very different flow rates of the reactors (biopellets is 2-3x higher than GFO) will cause issues such as the biopellet OUT overpowering the GFO IN which would prevent the GFO from working at all.

 

I thought of using a larger return manifold and pipe but I'm not sure if I'll have the height required to gravity drain to the sump.

 

Any ideas other than 3 return lines?

 

A sketch of the intended design is attached. Thanks in advance! 

[hypertech]

If its all down hill and the pipe is large enough for gravity to get the water back, you could try an air break (this seems fraught with danger of water on the floor though).  Otherwise I think you are going to need separate returns or check valves.

[kylewest]

is the air break required? any good way to figure out what big enough is? either way sounds like more hassle than $30 worth of pipe is worth.

[DaveS]

If its all down hill and the pipe is large enough for gravity to get the water back, you could try an air break (this seems fraught with danger of water on the floor though).  Otherwise I think you are going to need separate returns or check valves.

 

This is a decent idea that basically turn the return into a big sink.  But like a sink, if the other end of the pipe is clogged, things will back up and overflow.  My guess is that a 1"-1.5" would be big enough.  The less downhill, the bigger you would want the pipe to be.

 

All of the devices you listed are fairly low flow.  You may be better off running 3/8"-1/2" polyethylene or PEX tubing from each of them back to the sump.  All 3 bundled together will probably be the same diameter as 1" PVC pipe.

[kylewest]

You may be better off running 3/8"-1/2" polyethylene or PEX tubing from each of them back to the sump.

 

I think that's what I'm going to do: Run a 2-3" PVC or conduit through the wall then snake 1/2" PEX through that pipe to actually carry the water. Will make it easy enough to add more PEX lines if I ever need to.