Yeah a think ya right a think I'm in to big pots I've been watering when the top of me coco drys but with the plants being so small I'm going 6-7 days with out them drying now as there getting bigger it's every 3-4 days, I've been watering till a get run off to stop the salt build up should a not be doing that when I'm early veg?
Watering til run off is never a bad thing, but sounds like its your roots that's the problem if you were going 7 days until they dry out.
Coco is hard to overwater but when young plants with small root zones get watered too often the roots get problems and that can continue as they don't get chance to recover.
You have two options that I see, you can let them dry out far more between waterings or you can add a fuck load of oxygen by either aerating your water or adding h202(follow instructions) this will combat the root problems.
Two more questions, where does the run off go once it exits the pots?
Are they sat on a cold floor such as a concrete basement or cold tiles?