Runtz Muffin - First Ever Grow!

Well, when I was switching over to the MaxiBloom in the external reservoir, I noticed I had been using the incorrect scale for PPM. I should have just been using EC all along in hindsight but I noticed my PPM was way off when I was trying to follow dosing per the feed chart. I wanted to try it with the dosing first to see where it got me as I was just kind of "freebasing" with the previous mixture by adding until I hit the PPM. Well, when I did I noticed my EC was bang on but my PPM was hitting like 1100-1200 which was well above the minimum of 800 I was shooting for per the dosing. Turns out my pen was set to a 700 scale and my feed chart is in a 500 scale, and, luckily, it is adjustable. so that means when I thought I was being cautious I was actually dosing about 30% less than expected without deficiency. The Octopot creator recommends you use half dosage, so even at this comparably aggressive rate I'm not having any nute burn nor any signs of deficiencies. So I'm going to keep with the 30% less dosing in flowering and see how it goes, so I'm dosing at about 580 - 600 ppm right now (500 scale). Me from a little over a week from then: Well, that was a fuckin' lie. The stretch was too much for what I was feeding and had a phosphorous deficiency as a result which wiped out a ton of low growth. Luckily, I kept some of the low growth partially because some were stems I were hoping could reach the canopy and others were what I left in reserve. If you have a deficiency, it's likely a mobile nutrient, and that old, low growth can act like nutrient reserves and mobilize them where it's needed even at its own expense. In practice, you can give yourself a bit of a "buffer." I kinda needed that given this is my first time grow and I needed to feel out how I can work with the nute strength. Well, basically what I learned is: I don't really need to underdose with the Maxi series. I ended up bumping the nute feed up to around ~900 ppm without any nute burn and that's near the recommended maximum of 950 from GH for the feeding schedule I use.