I wasn’t exactly trying to experiment on this… but it looks like I did anyway. My last run, I finally ponied up for a bottle of OAC Cal-Mag from TPS. I couldn’t find any other organic cal-mags, so that’s why I chose this one. It states it also contains “a full array of micros including iron, sulfur, manganese, boron, and copper,” but doesn’t give ratios on them; guaranteed analysis on calcium is 4.5%, mag 1.1%.
Before starting to use this, I ran my Frankenstein and GG4 once or twice. I ran into deficiencies as soon as I started flowering them, and using standard fertilizers didn’t help. I also had hollow stems. Clones frequently failed to root. All-around bad, basically. When I added this to my water, the deficiencies largely cleared up and clones started rooting more easily. I wasn’t paying attention to the stems because I didn’t care - but a few days ago, I took clones of each and noticed that they have thick, solid stems now rather than hollow ones.
I’m planning to continue experimenting and see whether liming the soil between runs helps as much, and whether I still need the cal-mag with it. Should’ve been a no-brainer, since I have a rather large bag of garden lime in the garage for use on the lawn anyway, but my brain simply failed to engage and make the connection. Oddly enough, three days after I decided to try this, @Dirt_Wizard was kind enough to post this and validate my idea. 