FYI, if your tap water is not too hard I would suggest you just run tap water throgh it (measure it by gallons though, don't just turn the faucet on your plants) and just run gallon after gallon through it.

Then in the last 5-10 gallons start PH'ing your water to 6.5. This helps speed the process up SLIGHTLY.

You have 30 plants, you're going to be flushing for a long time. I only had 5-6 plants last time and it took me 1-2 hours for each plant.
daihashi Reviewed by daihashi on . New here but please help I have 36 plants in 3 gallon pots under 1000w hps bulbs. They did great through vegetative growth and looked really healthy up until about two weeks into flower, although I did not get the additional growth spurt I usually get in that first two weeks of 12/12. Starting week 3 yellow leaves started showing up, has continued to get worse, yellow,curling, brown and grey leaf edges. Also,the overall color of the plants has turned to a bright neon like green. I was feeding 20-20-20 for the Rating: 5