Best option for CO2 injection on 180 gallon drilled with a wet/dry?

[RukoTheWonderDog]

Howdy all-

I have resourced this site for many months; big kudos to Tom Barr and the rest of you guys for providing a ton of information.

I have run into a bit of a problem with my current setup. First, some details about the aquarium.

The tank is a Perfecto 180 gallon 72x24x24 with corner 1" overflows and 1" returns. The sump is a 50 gallon wet/dry with a throughput of 800-900 gph. Each of the two returns has it's own return pump.

The CO2 tank and regulator are in the basement. The reg setup:

VWR High Purity Dual Stage Reg
-Burkert 6011
-Ideal V 54-4-12 (My step father, a machinist, swears by SS over brass for needle valves)
-JBJ Bubble Counter

I have 3/16" hard tubing running into the pump pre filter housing at a 90 degree angle to the direction of flow. The CO2 line is split and runs into this hard line tubing. I have been unable to evenly split the actual flow of CO2 between the two sides by use of valves, tees, and manifolds. The CO2 always favors one side, and I have one of the pumps that always gets 90% of the gas.

I tried 3 different PVC reactor designs (the Barr style in 2 inch, and the Rex style in 2" and 3". I found that using the return pump(s) to mist the CO2 was much more effective than any of the reactor styles. I tried running these inline, as well as tee'd off of the main return and throttled down with a valve. I tried running the return back into the main return, as well as running a completely separate return. I always seemed to get large bubbles instead of proper disolution of the gas into the water. I am suspecting that the flow was simply too high.

The bottom line is that the current setup is not allowing a high enough CO2 level in the tank.

I have my finger on the trigger to purchase another ideal valve and run a second line for the other pump, but I am waiting in hopes of not needing to drop another c-note.
I am hoping somebody can help share some ideas that have worked on a similar setup. Any help would be greatly appreciated!

 

[Tom Barr]

Lose the bubble counter, you will not be able to measure the CO2 that way on a 180 anyway.
You also have positive suction pulling the CO2 at different pressures, so you will have some pull that favors one side vs the other.

If you place the intakes for CO2 farther away, this will help(reduces the suction pressure).
Use a small Rio 1000 or something to atomize the CO2 and then feed that flow into the return pumps(tee the outflow from the venturi pump to each return pump).

I think you need 2 valves, you cannot make it even otherwise with your current set up.
One valve and two differing suction pressures will never balance well.
That or split the outflow from a mist venturi CO2 pump(cheaper).

 

[RukoTheWonderDog]

Tom-

Many thanks for the suggestion. I have a spare MaxiJet 1200 for the Algae Turf Scrubber that I never used. I'll give that a try. If that isn't working as well as I'd like, I'll get another Ideal valve.

Thanks again- you have been a huge help.