Thanks all! The GPA and the AA#1 are 40 days old today, and the FB is 39. I took some time to measure ec and ph values from the runoff water, using water with ph 6.9 and ec 0.32. I know this ph is a bit high, but I had no means to change it ATM. I will comment about each one individually:
Green Poison Auto: I used 700ml to water this plant, and the runoff had ph 6.7 and ec 3.31!!!

After that I used another 500ml to flush some more. The last part of the runoff had ph 6.8 and ec 2.42. I think this ec is still high, probably too much... Anyway the plant is looking good, although there are some clearly clawed leaves. I will have to watch this one carefully. Now the soil in this pot is really wet, and I won't be able to water it for several days. I am thinking of flushing it again in a week or so, maybe using distilled water to get a good cleaning.
Assorted Auto #1: used 400ml on this one. The runoff had ph 6.9 and ec 1.10. I think ec is OK but ph is on the high side. I'm not sure if using water with ph lowered to 6 would help... I'll probably water the plants with such water to try to compensate. The Assorted#1 has some burnt tips, but looks like the less overfertilized one.
Fast Bud: I also used 400 ml on this one. The runoff had ph 6.6 and ec 1.78. In this case ph looks OK but ec is maybe a bit high. This one has a few burnt tips and several claw like leaves. Weird shaped leaves are common since it was born, however. And since it smells sooo good, I think this one is doing quite fine too.
Assorted Auto #2: I only poured some drops of water and root stimulator on this one. Obviously I didn't measure any runoff. I will probably begin alternating waterings for this mini coco experiment, instead of watering a little each day.
Summarizing, I wish I had bought these meters way before! I think my previous harvests would have been a lot better, and probably this one too. We'll see if these ladies do well with more care on my part
Thanks all for reading!
Bonus pic!
