1 gal of water every 3 days on drip system

Vegged in 5 gal pots of coco for 60 days then flowered in the same pot, different room for an additional 60 to 70 days depending on the strain, Veg lights being 1000w DE MH and flower lights being 1000w DE HPS. Nutrients and water mixed via an automated system regulating allotted dosage @ overall drip rate of 1 gal every 3 days.

That's a really slow drip, especially for a 5 gallon pot over 3 days. Why don't you flood it like and ebb & flow? You getting any kind of runoff at all? Pics greatly help here. I hand water 4 plants 2 gallons/day in coco in 2 gallon pots. I have 1 in a 5 gal pot that takes 3/4 of a gallon to get a decent amount of runoff. What's the ppm and nute solution your using?