Budd u honestly dont need to top feed man its what got u into the trouble ur haveing now. The bubbles in the buckets are going to create and push plenty enuff humidity and food up into the rock that will be entirely sufficient enuff. To be perfectly honest seedlings dont really like much water and i see it as a top problem alot of growers have rite from the start. I have grown 3 foot tall plants in just 3 weeks in just a bucket of water some food and an air pump n stone. Trick is just keep the rock moist. This will keep the wool plenty moist enuff. Id recommend getting the rapid rooters before the wool to anyone tho its almost like they where made for this system. Allow ur roots to grow into the water. Keep things proper let them rip and reap the benefits man. Really all the extra gadgets are not needed and will only more complicate the simplicity of growing this DWC.
Much luck anyway man.