A
ak-51
There was a really good setup several pages back which detailed an upper res and lower res, the lower one had a pump which constantly refilled the upper one. This way there was a consistent level of pressure on the lines. I followed that method and made mine with a 5 gallon bucket elevated and a 14 gallon on the floor. In the post I am referring to I think the dude had a pump running all the time to constantly cycle the nutes. I used a cycle timer to refill things because I couldn't get the bucket to drain as fast as it was filling up.I use a 5gal bucket as a res for 9 plants but I'm thinking of upping that because they seem to go through that in a day almost lately.
Here's the post by Rootz.