When you ask "does the air stone cause the reservoir to become moist?" do you mean the net pot/hydroton/rockwool? If so the answer is: not really. You have to flood the containers up to the level that will cover the roots. Until the roots are long enough, you can dip a cup into the reservoir and pour the mix on to the rock wool. Thus the roots will stay wet and grow until they reach the nute mix in the bucket. The level of the mix should be about as high as necessary to reach the bottom of the net pot. Whoever said let the reservoir go empty was being foolish. You really should get a pH/ppm meter and maintain a fairly full, level mix in the reservoir. You should check pH and ppm fairly frequently, perhaps daily or twice a day or more if you can. Don't let the reservoir go empty before you fill it. There will be ph/ppm changes every day that you should keep an eye on and maintain a level that is largely the same every day, to ensure that the pH/ppm values are where they should be. You also need a fan to push air around and blow on the plants to strengthen the stems, and get the humidity out of the area. I'm not sure that flushing is such a good idea. It might be better to just maintain an adequate pH/ppm level. I know people have a thing for flushing but I don't understand why. I is useful when too much fert is given, but other than that I wouldn't make it part of the regimen. If you discover a problem like roots becoming brown, then you'll have a problem like pythium or algae which will require thorough cleaning of all the equipment and that really sucks. 1/4 strength migh be okay for a short while, but you probably should focus more on the pH/ppm values, like pH of 6.0 and ppm of 500 and go up in ppm value as time goes on, usually to 1000-1200 or so as plants grow. Hope this helps. Frankly, I think DWC is easier but best of luck.