Hammerhead 4/10 is what I use and here is how 13/14 compares, right off the AN website...
Here’s Why Pk 13-14 Bloom Boosters Will Not Work For The Types Of Plants We Grow And The Gardens We Grow Them In…
If you’ve been following along then you’ve probably already identified the problem…
Because we are not growing field crops… not using outdoor soil gardens… and not using mass irrigation… we do not need a PK formula developed for those reasons.
Specifically, we don’t need a PK formula with such high amounts of phosphorous. In fact, recent research into growing using rockwool, aeroponics, and other hydroponics gardening systems has shown that too much phosphorous creates MANY problems for the types of plants we grow.
What happens is excess phosphorus accumulates in your crop’s root zone, where it can burn roots, interfere with the absorption of other nutrients, and severely harm your yield potential.
This is known as “phosphorous toxicity” and you can easily check for this by looking for brown spots or leaf tip burning with your crops.
What’s more: excess phosphorous in your plants accumulates all the way through to the final, finished crop-giving it a harsher taste!
The bottom line is, for the types of plants we grow and the gardens we grow them in, we need potassium (primary) and phosphorus (secondary) … in other words … you want to give your blooming plants way more potassium than phosphorus, in a ratio of two to one.