I want to start my babies in hydroponics! ALL TIPS APPRECIATED!

I have seen so many great things about growing hydro like it growing faster and delicious buds and low maintenance. My boyfriend and I want to get a deep water culture going but I need some tips. Such as: Why is the best cost efficient way to make a system at home? I pretty much have a list of the stuff I need after watching videos on building kits and seen diagrams so the set up is not so much the problem I guess. But one question that has me totally is stumped is; if doing top water feed can cause root rot, how is it that roots constantly being in the water not cause root rot? Also, will I be using the same nutes to grow with (currently using Fox Farm Grow Big 6-4-4 at 1/2 recommended dose ( I believe we used 1tsp per gallon) and Superthrive (1 drop per gallon). I know the water must be changed every 10 days, so I was wondering also what the smallest container I can use to grow just one plant to good size (not huge) 5 gallon bucket? And I read somewhere that the air stone should not run all the time, is this true? If so, what periods should it have of no bubbles? I know I have more questions but can't think of them all right now (damn pot head), but please if there's anything to give a pointers to a new hydro grower, let me know!

Hi there. Good luck with the move into hydro! Speaking from a new hydro grower (new grower in general) I'd have to say DIY system is so much better than pre-built units. My first ebb and flow unit was @ $223. My second was homemade for about $60. I posted in this thread cause I'd like to know an ideal pot size. The pots that came with my pre built ebb and flow were 5 x 5 inches. I used rockwool that I had to trim from a 6 inch slab to fit into these pots and I'm worried that since I've induced flowering they'll not be big enough and my roots will be stunted. As far as I know and intuitively I'd guess that airstones in a DWC should be on all the time since not having them on removes the aeration of the water and would simply drown any roots that are hanging out in the water?