Is this your home, or a rental? If it's your home, you could keep the res in another room, with a couple of hoses poked thru the wall.

Or, you could top the clones to stunt vertical growth a bit, or go with the bending and tying, but with that many plants, would be a bitch. Have you tried using MH during first couple of weeks of flower? (tiz supposed to slow stretch early in flower)

Or, you could figure out the mean average of water intake before run-off, (2 cups, a quart, a gallon...) keep 'em on the ground, and water each accordingly. I've always restricted run-off, but I do monthly flushes which helps to alleviate salt and nute build-up.