Your flush rule is correct.
Hanna meters suck furry monkey balls. I've seen people kill their plants trusting those worthless pieces of CRAP. I'd trust the liquid better in general, and cross-check on the regular.
ProMix is appropriate where your plants will be repotted approximately once per month into fresh promix.
After teh flush, feed with a 1/4 strength complete fertilizer. You may also do a foliar feed of the same to help jump-start the deficiency correction.
stinkyattic Reviewed by stinkyattic on . Wierd yellow and Brown Spots Please Help These Clones are about 3-1/2 weeks old, still in veg 24/7 schedule. Half are in Bio Bizz Coco mix with perlite and the other half are in some Premier shaphnum peat moss with perlite and some dolimite lime. They are both showing the same spots so I dont think its soil realted. I am feeding them Botanicare Prow Grow, Liquid Karma, Cal-PLus Grow from advanced, with R/O water. They get feed every 3-4 days when the pot feels dry. I have been trying to give them 2 normal strength feedings and then 1 Rating: 5