I would keep feeding them nutes every watering until the last 2 weeks, then pure water the flush them out. Do not wait as long to water them. You want the bag to feel light and the medium to be dry but not bone dry.
What size bags are you in?
Also, loosen up the first half inch or so of dirt on the top of the bag before watering. That will help the water penetrate the dirt evenly. It seems as though they are using more nutes than are being supplied so I think you would be fine every feeding. If you start to see nute burn back off the nutes to 1/2 strength.
Keep them pics coming!!