I’m about 60 days into my first Autopot grow. I have nothing but good to say them. 
The Autopots.
4x4 tent, light was 600w MH in veg, 1000w HPS flower. 3.9 gallon pots, substrate is 50/50 Canna coco mixed with perlite. Nutes are Canna Part A and Part B full strength, CalMag. I added Canna Boost about 2 weeks in flower as recommended. Light cycle was 20/4. However after discussing with Autopotomous, he suggested going straight 24 hours.
Anyway, back to the PK 13/14.
I read mixed reviews all over the Internet. Reports like, “burned all my buds” “did nothing” “waste of $$$” while others said “its great”.
Well I’m here to say for me it worked great. Amazing. But I sided on caution. As suggested by Canna, I mixed the PK directly in with my regular feeding of Canna Part A and Part B, CalMag and Canna Boost. However, I only mixed the PK at half strength in a 4 gallon feeding. The plants drank it right up in 48 hours. I did a second feeding, but this time added PK 1/4 strength.
Canna recommends feeding your plants about 2-3 weeks into flower, for 3-6 days. However I stopped feeding the PK after 3 days.
The results were amazing. My buds exploded in the brief period. The PK bloom booster and precise timing worked. When I unzipped my tent bud laden branches immediately began pushing out the opening. When I closed up the tent, I was pushing branches back in.
I’m running a 1000w HPS, which I had to dial back to 75% due to the fact the buds were getting too close and I was concerned about burning. However, the four plants have absolutely taken over the 4x4 tent. I decided to add some small LEDs on each side as supplemental lights, since the HPS could not adequately cover the entire canopy.
I’ll post pics when I take some tomorrow. But I did take a pic of a bud from the Speedrun Acid Snow.
