Critical Autopot

The first week of blooming went well. The girls like the autopot system, and I'm very happy with it as well, I wish to only grow this way in the future. I filled the water tank with ca. 90l nutrient solution 6 day ago(about the same time I flipped them to 12/12), and now there are 25l left. I've been adding a bit of Ph down every 2nd day, since it kept going up to 6.5. I really wish it would stay more stable! I added a bit of PK(0.25ml/l) to the feeding, in my experience it helps the girls to start blooming. Since the water in the tank started getting murky, I started adding H2O2 to try to keep things under control. The girls have visibly stretched. So far I've been doing the minimum amount of training, topping twice and binging down the top shoots, I hope I get some time to do a bit more soon. Oh, I've also been removing the lowest side branches, I want to avoid the popcorn buds as much as possible :)