Popscotti was probably one of the most resilient strains I've grown lately. I have a mother that I have literally tried killing several times and it just comes right back without any issues and handles any amount of EC I could throw at it. Huge buds but the flavor wasnt that great at least for...
I have the bluelab ph pen and truncheon. Also if you have the extra cash to spend I recommend investing in the bluelab PH controllers. So far they have been a godsend for me, I never have to worry about PH swings because it always locks itself back to 5.8 fairly quick after draining.
Honestly I have the best luck when I just run normal tap water and don't worry about anything else. My tap water is usually a high ph of 9 and ppm of 300. I don't PH it or anything and have had pretty much 100% success. When I first started I kept worrying about the PH, temps, ppms ect and ended...
Yea rockwool can have salt build up its why my guru taught me to always do a 24 hour flush when changing res before adding nutes. Also I recently switched to Jacks RO and it has made things a hell of a lot easier and my plants love it.