tim85,
Yes, the unions are expensive, but I have a 384 and 584 and can now switch them in moments.......if there is a need.
Here is a thread with a bypass with simple pvc:
http://www.barrreport.com/co2-aquat...uestions-observations-2.html?highlight=mazzei
You can make a bypass loop out of flex hose as well......quick and inexpensive to make the loop to see how it works.......and make improvements.
I know the LFS sells in-line ball valves that have barbed ends. Just slip the flex over the barb and you are good to go. The mazzei has threaded ends and they sell connectors that are threaded on one end and slip barb on the other. so flex hose fits right on..........now venturi is connected to flex and rest of loop..
Here is a thread with an example:
http://www.barrreport.com/articles/2282-diy-external-inline-co2-diffuser.html?highlight=mazzei
Some folks switch the control ball valve and venturi positions. The straight leg will get more direct flow/pressure and make the venturi more efficient.
I used flex hose for my first two attempts before I built that thing, trust me lol
Don't forget to place sponges over the intake strainers and to rinse 2x a week!
I would place a ball valve both before and after the pump. You will regret it if you don't....
Yes, no issues if the pump goes off. You will have a closed loop if you connect the intakes to the T and then the pump, and then the outlet goes back to the tank...
You do not have a sump or overflows do you? That would change my answer in a big way.............
How do these holes drain and where exactly are they?
Details please. I do not want to be the cause of a water overflow!!!!