Charcoal fines are eliminated after running the carbon filter for a few hours while giving it a gentle tap here and there.
So rkymtnman, how would you aerate 36 separate 20 gallon bins? With 36 separate water pumps?
My aeration system (my entire grow for that matter) is only visited once or twice a week and because of the clean room methods used to filter the air supplying the air pumps, I have not had an air stone fail since implementing the system and the performance of each air stone is measured separately. Water pumps simply cannot push the amount of water that evenly dispersed air bubbles will achieve for the same amount of energy used.
Add to the fact that some people want DWC containers that are not plumbed together (to eliminate all possibility of root clogs in the return lines) and the only solution for that is an air pump. Any mechanical engineer knows that the most efficient way to move water is with air. That’s how snow makers work for that reason.
My air pumps (pondmaster ap-100’s) go 4 yrs without a diaphragm change. 1.1 amps @123vac perfectly agitates 6-20 gal Rubbermaid bins (filled with 13-15 gal of water). If you were to divide the output from the volute of a 135 watt hobby water pump to waterfall into 6 separate containers you would not achieve the same evenly dispersed agitation that air pumps (more properly known as blowers) would achieve. Plus you never have to worry about clogs/leaks or floods due to plumbing/root clog issues.
Look at how aeration is achieved in all other industries. When you go past a small amount of containers you are left with no choice but to use a blower and aluminum oxide air stones simply because of the incredibly (almost 100%)
reliable and constant performance. A growing root ball does not effect the blower but it sure will clog the return line feeding your water pump.
Plus, if you use flow meters to monitor the air output, you will see when air output starts to diminish. You just change the diaphragm of that blower while the other blower keeps pumping air through the other air stone. You use at least 2 blowers and 2 air stones for each bin. This way (after about 4 yrs in my case) when you change one diaphragm, you still have another blower forcing air through another air stone.
With blowers you will never have a failure because the flow meter will show a reduced performance way before the diaphragm breaks. The blower diaphragms never fail abruptly. They “talk” to you monthsin advance by showing a slight reduction in performance.
Water pumps, on the other hand, do fail all at once when the roots grow so much in a few days and clog the return line feeding the water pump.
I stated my case with logic and experience. It is not scientific to simply write “swing and a miss”. So rkymtnman, do you have a plausible counter-argument that includes...facts?