Clones are already mature plants. That's why they started to flower. Like people said plant clones in may unless you have extra light to extend light cycle to 14 hrs.
I'm a soil guy, but if you stay away from organic nutes in the hydro setup then you will avoid nasty issues like root rot and having to constantly change your res.
Hydrogen peroxide mixed in water will help kill em. Just don't mix it to strong. Also you can add an inch of sand to the top of your pot. This will help keep the adults from laying their eggs in your soil.
Is your light on 24/7? You should be giving the plant a dark period of at least 4 hours. I have my seedlings under cfls in a cabinet with a humidity dome.