Ziggy:

'xcuse me but..... needing a sump pump to get the nutes back into the reservoir (and another one to pump them to the buckets) is more complicated than one pump recirculating them.

The sump pumps you're talking about are good units, heavy-duty, relatively cheap for how much power you get. My $60 one [a Wayne] from Ace wil easily pump up to a 7' height above the pump, with a flow rate the same as my house water tap wide open. But........ they're hot! Left one in the res accidentally turned on overnight a couple times ---- could've cooked an egg in the reservoir soultion. :stoned:
So they couldn't be used for continuous duty, no way. Great for emptying reservoirs, great for watering soil grows (watering your pots with water/nutrients mixed in a reservoir).
Here's your float-switch links:

http://www.acehardware.com/product/i...Id=10509336467

and

http://www.acehardware.com/sm-wayne-...i-2151136.html
grow4fun Reviewed by grow4fun on . How does Aquafarm/Waterfarm Recirculate Solution? I was looking at the Waterfarm (buckets attached to a controller-bucket), and wanting to build a system like it, but I want my system to be re-circulating. Where the nutrient solution in the bottom of the buckets is constantly flowing into the buckets, like NFT/SWC, and back out. Iā??ve read threads on the construction of Krusty buckets and DWC buckets, but no-one explains the path the nutes take through the lines and buckets. Some (like Waterfarms) only have a single Rating: 5