Thank you for the advice, ordering a meter, also growing in miracle grow regular with about 25% garden coir, and about a 1/4 cup perlite mix, in 3 gal fibre pots, think i need bigger pots, these seem to dry out to fast, by day 2 or 3 need to water. The nutes were being used according to the grow chart i had but looking at it, looks like was specs garden coir only , not a mix with miracle grow. Since miracle grow has some nutes already every time i water, adding the extras even with the mix recipe may be to hot. Using a qb288 xl for lighting, slow circulating fan at plant level, exhast/humidity control on exhaust, have no c02, can you recommend.?