I watre my full grown plants maybe once a week in 3 gallon pots which are not massive by anymeans 3 gallon pots are quite small 30 gallon pots are big.People use digital ph pens as they are more accurate and cheaper then paper test or liquid test kits. You can get a good sunleaves or hana new on ebay for about $28 bucks shipped...That 2 gallon res dictate has is way to small for 6 plants.A 6 plant setup for gamja should be no less then a 20 gallon res.You got a grow setup for dill and parsley my friend..Where did you find a 1500 watt mh light from never seen one ever?? and yeah 6 inch plants under 1500 watt lights can be a little issue if they are from seeds