[SmokeyMcBlunt]

Ahh took me a minute to figure it out but I got it. 24/7 should work fine *if* you keep your water oxygenated and at the proper temps....64-68.
If you dont mind a critique of your design, I see a thing or two that you need to change or improve upon plus a question or two.

You better be growing some small plants because it looks like they will be on top of each other. Why not go with the same idea and cover 3/4 (or all?) of the res with spots. Space them out some...plus add a hole or two for more plants. Speaking of which...

You are gonna have a bunch of roots in the small tub so make sure its big enough to handle a bunch of roots without totally covering your sprayers. It just doesnt look big at all. I pulled out 5 pounds of roots from *one* sativa last harvest in my aero. Roots can go wild in a good aero setup. I really suggest a bigger tub for the plants. Speaking of which....

Since you are only running 3 plants get feminized seeds or female clones. With only 3 spots you could easily get all males. That 17gal res is way too big for only 3 plants IMHO. I cant stress enough to make sure your res temps are proper which is harder the bigger the res is. Speaking of which....

Are you going to cover the res somehow to make it light proof? If you can keep your water temps in line its not a big deal but if your temps are higher than 70 you *really* need to lightproof it. Algae will go nuts in there otherwise. Do yourself a favor and get Hydroguard and Hygrozyme to keep your roots healthy and fend off root rot.

Hope this helps!