Get yourself a timer. They are about $2. Saves a lot of hassle.
As far as I know Ph is an issue with soil too. If you get good soil and don't overfeed with chemical ferts then I think you will be ok. I flush with a gallon of water first then feed with less than half a gallon. You probably won't need to water at this stage more than once a week. You'll know you've over watered if you see mould or fungus gnats buzzing around. And the plants will look sad. I like to flood mine then let them dry right out to the point when the leaves start to droop. Don't get confused with leaves drooping for other reasons though. They sometimes do it toward the end of the 18hr light cycle because they are getting tired and ready for some sleep. Or if you over fert them. Better to half feed and worry about deficiencies than over do it.
Also, I think if you flush them too much you wash out the lime in the soil and end up with high ph so itâ??s worth lashing out on a ph tester if you are really concerned.
BobBong wisely says â??water for the size of the plant, not the size of the potâ??
Not 100% on this one but Zandor says miracle grow products are crap.. including the soil.
One post I read the guy said his miracle grow soil was full of spider mites!