Quote Originally Posted by doco
Looks fantastic RacerX, but I would not have expected anything less from you. Your advice always has the tone of experience behind it but this is the first time Ive seen it in action.

btw, what size pump do you recommend for the recirculating bucket (that feeds back to the res)? I'm going to get a Waterfarm going and liked the way you did the recirculating waterfarm on that thread.
For 16 buckets we use a 350 GPH pump. This is plenty and the feed line into the buckets is pretty strong so it spatters against the netpot, keeping the Rockwool moist, and helps create that humid environment between the water and the top of the bucket. You could get away with smaller pump but it wouldn't be as effective. A larger pump would work as well, but the water might come out a little too fast. With the 350, it takes less then 10 minutes for everything to completely recirculate which makes pH balancing and nutrients a breeze; add stuff, wait a few minutes, double check, and your good to go.

One thing I will definitely say is absolutely necessary is the gravity reservoir. We thought we could get away without it and just add water/nutes on our own until we grew comfortable with the system. That was a mistake. The plants are so huge and hungry that they drink about 6-7 gallons of water a day...atleast!!! That means I am topping off with water and nutrients everyday which is sort of a pain. With a gravity fed reservoir that has a float valve, everytime the water gets low...more is let in. Luckily we already had the parts for it.

Last, if you are able to get a water chiller (something that is almost mandatory for DWC), remember that the chiller itself does not have a pump. You must pump water through the chiller so a larger pump is sometimes needed. This depends on the # of buckets, the amount of water you have, the elevation of the tubing, etc.

For DWC systems, the feed line can do whatever you want, but the return line must be COMPLETELY even and flat against the ground because it uses gravity to drain. This means that if one of the return hoses is an inch off the ground, it is not draining correctly and not getting the flow of water it should have.

To date, we have had absolutely no leaks whatsoever.