Sounds like you have one of two issues. if it's dry then the drip tube is clogged or not close enough to water the plant but don't think so. I think the drip tube has been right on top of the root riot cube. If the riot cubes stay wet all the time the airball will drown, turn yellow and die.

I have run drip from constant to 15 minutes every 4 to 6 hours. constant is kind of hard because of the airball problem. all other roots can stay in water 24/7. So watch those starter cubes. I would do 15 to 30 minutes every 4 to 6 hours. less when they are small. more feeding when they get big.

rule of thumb on the nutes in your rez. when you have replaced all thwater in the rez with top up water it is time to change. So if you have a ten gallon rez and you top up your rez one gallon every day in ten days you need to change your rez. do not not top up you rez. if you don't top your rez everything in it gets more and more concentrated. plus your plants piss off waste in your rez. change two weeks max even if they don't drink that much.
LOC NAR on probation Reviewed by LOC NAR on probation on . Feeding regime Hey, this is my first grow, using a wilma pot big 4 with just clay pebbles, with canna aqua vega a and b. the plants are in little root riot propagation cubes and are 4 weeks old from seed. Just wondering how often to feed or too keep the nutes flowing ? Got three on the go at the moment under a 400watt hps, with plenty of ventilation and air movement, 2 of them seem very happy although the third is a little dry, and curling under with a few brown spots although very tiny and a little Rating: 5