Ya I kinda figured it out last night,lol you got me thinking.
so say you have 40 buckets, 3 gal a bucket, 120 gal on a slow fill. The first bucket might fill slightly faster but once all 120 gal is in the system the weight of the water and gravity would make all the buckets the same level. Now if it was a flood and drain system or drip system you might run into prob. but since the water fills and sets it will level in a mater of a min. Very kool... I wanted to use your same basic princable but go areo instead of dwc, and have the drain always open. I figure I could take the 130 gal change every week and bring it down to about 30-40 gal saving up to 100 gal of nutes a week.
