Thanks for the quick reply stinky; I've been watching my meter for about an hour and a half now and the ph has stayed at 5.6. Hopefully this is a sign of things to come

Would a guess that the clones are about 3 weeks old sound accurate? There are roots coming out most sides of the rockwool, about 1-2 inches in some places.

Today I am going to be working on setting up a screen of chicken wire about 10 inches from the planting medium for a SCRoG when the ph has stabilized.

For now, I need to figure out how to flush my system. 15 gallons is a couple too many for me to be hauling the damn thing down the hall to the sink to drain. I was thinking using my level indicator as a siphon and adding a gallon as it drains out. Whadda ya think?