When using the PK 13/14 in coco do you have a recommendation on the strength. It says something like 1.5ml per gal and I have heard it is a good idea to start with like .5ml and work up to 1ml in coco. What have your experiences been? I have also been doing some reading and I am considering a PK 9/18 (hammerhead) Any thoughts on that too?
i think your mistaken on your feeding measurements.
But to answer your ?... it depends on how long you want to use the pk 13/14 for...
if you only use it for one week than i would just use the full strength (6 ml per gal.), If you plan on using it for longer, then i would use like 4 ml. per gallon.
As for the Hammerhead 9/18, I do use it, but it cost twice the price as Canna's pk 13/14 and it recommends using more for much longer. It works well but i dont think its works twice as well (it just cost twice as much)...
These days i use it at 4ml per gallon during week 3, then i switch to canna's pk 13/14 for weeks 4 and 5. And then i use shooting powder and gravity for weeks 6,7, and 8... this along with several other additives, has increased my yield by 20% compared to just following the Canna feeding chart.