all good questions.. my question is WTF lol.. no idk man im jus bein a dick by saying that idk ur situation EXAAACTLY so idk if this will help but if u can, heat the bottom of the tray and put about 500ml of phd water in it, or just keep using distilled water, distilled water is usually about 7.0 ph so not that bad, but ya considering ur using rockwool (use rapid rooters next time, might b called something different where u are) u want to balance the water to like 5.5 cuz the glue in the rockwool can make the ph pretty high. Now idk what size tray u have but thats the amount i put in mine so it fills the tray about a third of the way, becuz ur using rockwool, again, ur going to mayb want to airate the water with an airstone/air pump whatever. Heating the water not too much, i think the right temp of water is like 27 degrees celcius (canadian temp) idk but not hot or n e thing right, just enough that it evaporates over 5 days with the dome on it with the vents cracked a quarter of the way, this will make ur dome rediculously humid and u will have fat roots in 2 weeks, this has worked for me 100% i swear, so simple. Idk what ur grow is but if its a mini SOG or something ur going to want to invest in a heating pad with a temp on it look up what the right temp is for rooting and just let that shit get humid man.. mayb i had 100% cuz of the strain i had, just a lucky kush strain i came across was perfect for everything. Like i used rapid rooters and tap water and a little nitrogen sometimes even (not recommended usually to be honest but i didnt have a problem with it) and i didnt even airate the water in it.. i just let that shit go dry till the actual rapid rooter was getting a little dry then id fill it up again, i think id fill it up twice n that was good. hope that helps, lots to read i kno, but its late im baked and bored and u were the victum. in this case i hope helped aswell. keep em green dude peace