Do you need to keep an airstone with the nutes in the res with these things?

I don't. I have not had any problems whatsoever. The system is superb.

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One sec...I am trying to think of something clever...
Got CFL? http://www.rollitup.org/cfl-growing/71259-cfl-sog.html

What exactly is the point of an airstone in these things Ive read its better to keep your water circulating.

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I do not condone any use of illegal drugs unless prescribed by a health expert... such as Dr Dre.

I use 10 of them, GH nutes, lucas formula, airstone in reservoir to provide oxygen and to keep it mixed. Perpetual SOG style, two 600 watt lights, 2 reservoirs, bla bla bla

Anyway, I love the low maintenance as I am lazy.

PS. AN nutes do not work well with them, too much sediment. It settles in the reservoir, the lines and clogs the smart valve.

Good luck

i run a 10 pot auto in grow i keep nuets at 0.8 to 1.2 then in bloom 1.8 4x600 hps good results iv found

I am trying my second crop first went well to start with then suffered leaf burn. This time had same prob even though I droped the strength. Think the problem may be as there is no drain for the system the roots eventually release excess nutrient into the tray starting a vicious circle of toxic build up. Take the pots out every 1 to 2 weeks and flush with 1/4 nutrient see if that helps?

Nice LED panels. Did you make them yourself?