I used Gravity on 3 alternate grows with different usage amounts and times.
The strains were Blue Dream, Purple Urkle, PitBull, Cripit using General Organics nutes, with Rhino Skin, Purple Maxx Snow Storm, and Sweet (all at manufacture directed amounts), in soil, under multiple 1000 watt HPS.
The gravity was applied to 10 plants of each strain grown from clones.
The first trial used the manufactures directions and resulted in mild burn on the first application, repeat applications caused further burn. Harvest was 5 days early based on my preference of amber/opaque trichs. At harvest all sun leaves were gone and most of the leaves on the bottom halves of the top buds were dry and suffered mild burning. The damage was on all the buds of each branch. Yes I raised the lights.
Also I had herms on the Pit Bull and Cripit. (see warning of tendance to herme) resulting in seeds in some buds.
The buds were very very dense after curing. The Blue Dream was "almost to dense" they were almost hard.
So I thought it was a good product if I could get the schedule correct for my strains.
The next try I used half the directed amount and only watered with it in a non-nute clear water watering. For the last 3 weeks with raised lights. They did not burn. At harvest, 5 days earlier than my non-gravity grows, all the leaves and bud were in a healthy condition but I was still getting hermes on the Pitbull and Cripit.
The buds were very very dense.
If you have a strain not prone to herm this schedule would probably be ok to start from. Pitbull and Cripit are crosses of the same strains and Gravity seemed to effect them differently than the Blue Dream and Purple Urkel.
The best overall grow for me was to use half the Manufacture amount, 2 times in clear water 10 days before harvest without raising the lights.
I found this stopped the herms ( i suspect because the plant didn't have time to herm and pollenate before harvest). The buds are extremely dense and my finish weight is up 10-15% over the non-gravity grows with no change in flavor, aroma or potency.
My next try will be:
On the Pitbull and Cripit I will be using half dose, clear water 2 cycles in 10 days after stopping nutes. IE: last nute appplication, 5days later Gravity appplication, five days later Gravity application, 5 days before harvest.
For the Blue Dream and Purple Urkle I will be using half dose, clear water, once 5 days before last nute and 2 - 5 days cycles after stopping nutes till harvest.
This should work unless it makes my Blues and Purples to dense.
If that happens I'll swing everything to 2 half strenght, clear water applications 5 days apart after stopping nutes.
I really think the latter is going to be the best usage.
Be very careful using Gravity during nute application burns and not slowly or reversabley.
A word on mold: I don't currently have a mold problem because of where I am located and good preventive measures. Using Gravity the buds are extremely compacted. When I broke a bud apart at harvest they are very wet with large amounts of fluid reserves. Much more then my non-gravity grows. I can see how mold could easily start in these buds.
I would recommend watching your harvest time closely until you learn the impact on your strain.
After curing the nugs are true nugs!
