Don't be a sheep . been using the same air pumps that came.with the system for two years now still hitting 11 lbs on 4 1k with the double barrel 16 8gal. I'm actually looking to decrease my yield.
Focus on more.important shit like a correct nutrient profile or ideal VPD .
Decrease your yield? I'm all about quality & pushing the envelope been striving for bigger,stickier buds a lot of years. But never seen yields like that unfortunately and definitely never looked to decrease my yield. I too run double barrel systems 16 & 24 site. 11 off 4K is killing it. Good work bro!
As far as airstones I upgraded to glass airstones & clean and reuse each run. Using 2 per module. On my 24 site w/13gl modules I doubled my air pumps to now 1-afp80 per 6 modules & a afp40 on epicenter. Also run a little larger return pump. Next size up from recommended Danner Max drive. I've tried larger with little noticeable difference. Off my air pumps I run the least amount of the 3/8" poly possible making sure each is same length so every module dispersment is equal. The glass air stones helped a lot.