So when it comes to an air pump what is the minimum I need in CFM? I have a 1 acre pond max depth is about 9 feet. I thought I remember reading I need at least 1.5 cfm but wasn't sure? Can anyone enlighting me on this. I don't want to under do my pump but at the same time I don't want overkill either as the price can get high quick.

Thanks,

Depends on what your diffusers require. If you are using membrane disc diffusers, they require a minimum of .5 CFM each to operate (max is 2.5 or 5 CFM depemding on slit size) I try to get 1 to 1.5 CFM per diffuser in case there is an air hog.

When I design an aeration system I try to achieve atleast 3 CFM at each diffuser. I do use the air stones from aquatic eco systems rather then the rubber diffusers. It is important to remember when sizing the pump for CFM that you will have frictional lose in the hose and atmospheric pressure due to depth of water.

What did you just say me??? Ok I guess I need to read up more on this before I pull any triggers. Thanks for the help guys.

Always lots to learn...lol

With 9 foot of depth and assuming you will only require 100' of 5/8" air line, the pressure required will be 4.16 psi.

Everyone is right about the cfm depending on the diffuser types. Rubber membrane be it disc or tubes require 0.5 cfm and the stones require 1.5-3 cfm.

A round, 1-acre pond should only required one diffuser station unless something like intense aquaculture is being done in the pond.

Best fishes! ><((((*>

Hey thanks Cary. The pressure at 9 feet is a good thing to know with the 100 foot hose at 5/8 in. I been looking at pumps that push 6.5 psi so I guess I am ok there I figure I could put the diffuser at the 8 foot mark and be in the 3.7 range of pressure then my pump wouldn't work so hard.

RC51. look at the CFM curve for any low pressure pumps...Most state the max CFM at 0 psi....A 6.5, 5cfm pump may only put out .5 cfm at 5 psi.

Hey Rex thanks I will. Like I said i am not pulling any triggers to soon on this. I want something at a decent price but I also want to make sure I get the right thing too.