yeah i got the idea from your post. after the roots touch the water - wouldn't it be overkill?It really depends on what you want the bubbles to do. if just oxygenate water, then one of these would be fine
http://www.discount-hydro.com/productdisp.php?pid=412&navid=8
But if you also want the bubble action to be enoughto water plants until roots are in the water per the link below then one of the above to each res, and 3 or 4 12 inch airstones for each.
Maybe and you could go to 2 stones and one pump when roots are well into the water. But it would be more hassle than it was worth IMO, and you need the extra bubble power in the beginning. Either way it's easier than pulling a water pump and tubes. Also, when you have two pumps, you always have a backup just in case.yeah i got the idea from your post. after the roots touch the water - wouldn't it be overkill?