Diy Rex Griggs CO2 reactor Questions

[WET Aquaria]

Looking to DIY a griggs reactor for a 180 with a from 75 sump. The reactor will run on a standalone pump and draw and dump into the return section of the sump. Planned design is 3" pvc tube at 28 inches high. I would like to build a bubble counter into the reactor intake instead of the primary tube.

1)Do you see any issue with the bubble counter design (I think the height and diameter counter the bubble being swept in the current)?

2)What would be the recommended gph for the pump?

3) Thoughts? I am able to move to 4 inch pvc if needed.

[Phishless]

I would isolate the bubble counter from the reactor inlet with a check valve.
Returning to the sump may require two reactors, tank is large >250 gallon of water to inject.
Possible to put reactor output directly to tank via spraybar?

Have you thought of using a mazzei injector and skip the reactor?
There is also a "cone" often used on large systems but very expensive.

This must be a reef tank conversion, no one seems to be able to part with a sump!

[Cristy Keister]

Yes, your reactor should go to the main tank, not the sump. You would lose a lot of co2 in the sump before it's pumped up to the tank.