Hey Bert!! I think your 30 min flood is to long. I do 15 min floods atm and as soon as I get a digital timer for the pump I might be cutting it down to 10 min flood times. I start germ'd seeds or clones in 1" RW and graduate to 4" cubes. Until they get set in the floodtray I hand dip each 1 in a bucket and even with the 4" cubes they only have to be dipped for about 5-10 secs before the cube is "watered". I think the next grow I do I will take the time it takes to flood the tray and add 5 mins to it and that will be the flood time.