Cecil, I have reread your original post 3 times and it is the same each time
I read it as 3 small tanks at 3 ft and one 9 ft depth the first time.(Feb 25th)>>must be the cold medicine)Your 3 ft depth obviously 1.5 psi is not a problem and perhaps 3 of them would not of been a problem and then AES would of confirmed the result of the single 9 ft depth in conjunction. Since this is not the case that linear pump (SL 94) wont work.More reason to run your numbers past your aeration supplier for confirmed results.Even if you were able to squeeze some air to 9 ft it probably would not be enough and very difficult to keep regulated. I do not know your pond size but believe you have stated in the past they are small and intense.Do you know how much air you want/need in the 3 nine ft ponds. The max I would figure is 2200 gallon per minute turnover at 1 cfm for each pond. This may be more than you want.Do you know what your current diffusers are turning. If not when you did a DO check in warm water on a cloudy day and have a 7 mg/l (or ppm) reading or maintain 80% saturation regardless of temp your diffuser/s are doing OK. GENERAL RULE for most pond that if you are not turning a minimum of once per day (entire water body)you arent aerating properly or lets say receiving all the benefits aeration should/ can provide.If that Easy Pro is 4.7cfm at 8ft and not open flow I could see that working depending on the "back pressure" not "pressure" of the diffuser. The diffuser pressure will be just under 5 PSI.Calculate about 1.5 PSI to overcome hose friction loss and most checkvalves at that depth no matter if its a stone or a membrane diffuser.The exception would be a fine airstone or a membrane diffuser that was slotted with less than 6500-6600 slits per 9 inches of surface. (we wont get into I slits VS Y slits and .5 mm holes VS 1mm holes) The Gast you have now at 1/3 HP has been replaced by a 1/4 HP model and pulls about 4.2 amps but will give you 4 CFM at 9 ft, model 0523.Still 4.2 CFM open flow.I looked in a Stoney Creek cat for that Easy Pro spec but did not see it.I size to maintain at least 80% saturation and or 7-8 ppm minimum DO. Trout water and various other cool waters can be a problem with this formula but slowing up the circulation to maintain cooler water and attaining a higher % saturation of the cooler water seems to work just fine. Trout goal is 10 ppm and the opposite is carp that can survive on 1-2 ppm DO, Ted
