Gerry:

Basically it's designing the system to utilize all the air from the compressor. The compressor is sized to meet the diffuser needs. All that is done is balance the "boil" between the diffusers via the ball valves. Diffusers in deeper water require more pressure than diffusers in shallow water. I have seen an extreme example of a diffuser in 12' of water not getting any air because of the shallower water diffuser using all the air - path of least resistance. That's why you balance it manually with a ball valve going to each diffuser assembly.

I have field bred ESS vs. Show bred ESS.

The field dogs have MUCH more white in them - easier to see, etc., etc.

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3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).