helllo all any advice would be helpfull. i am running a 35 gal eurogrow system,reverse osmosis h2o, 1000 wt hps, lucas fomula 8/16 gh nutes with eight casey jones planets water temp 70 ,room temp77 night 70 . i am into my third week of flowering but i am expirencing huge drops in ph say from 6.2 to 4.8 in less than 8 hours with my tds only rising 80 adding a shit load of ph up. my plants look great. is this somewhat normal? i do change the system weekly and add pure water every other day.