Set up submersible heater keeps water at 79F 20-30 gallon air pump going into two air stones RO water keep plants around 1/4'' above the level of the water. 8 clones 1 26W 6500k floro light 2 feet above clones on 18/6 cycle I cut clones bout 3 weeks ago 6 of 8 of the originals have been replaced because they yellowed up to much or started to shriveled up, or got blackish brown on tips of small growth. At first i tried to adjust the ph to 5.5 to 6.2 and two drops of super thrive in 5 gallons of water but the ph was all over. I read that i can just use plain RO. They have been in plain RO water for a week. the ph of RO water after a week is around 8 originally it is around 7.2. Do I need to lower this? I cut clones with a clean knife then cut a 45 deg angle on them under ro water then scarped up the stem a little in one spot and set them in some cloning gel for 30 seconds. and put them in the cloner a few day ago i ready about splitting the stem ends so i did that trying to get them to root. The newer cut clones were cut from budding plants so this will make it harder here are some pics, any suggestions why they are not rooting