I tried to use Sledgehammer per the feeding schedules but I think it did more damage than good. My plants were healthy but I decided to use it about halfway in flower...when I was transitioning from open sesame to beastie bloomz.
My plants were in 3 gallon pots and at the time I watered with 1 gallon or less and saw run off. I flushed with sledgehammer and used 3 gallons of distilled. Apparently that wasn't enough water, even though the last 2 gallons ran right through the soil. After some research I found out that the active ingredient in sledgehammer is a strong surfactant. It helps water flow easily through the medium...that makes sense since it is a flush right?
Turns out that the sledgehammer remained in my soil for longer than expected and my plant developed multiple deficiencies. The subsequent feeds were flowing right through the medium and washing away any nutrients that remained. I found this out because I had the same strain growing on the same regimen that wasn't flushed with sledgehammer and it showed no deficiency.
I obviously made a big mistake administering the sledgehammer but my bigger mistake was blindly following the FF schedule.
In my opinion, I would only use sledgehammer if there is a major salt buildup, pH problem, or for pre harvest flushing. If you are hellbent on following the FF schedule then make sure you mix the sledgehammer in 1 gallon and then flush with ALOT of clean water to rinse it out of there.
As for feeding at the same time you administer sledgehammer...I think it is pointless. You are flushing to cleanse the medium. Why would you add nutes? Plus the sledgehammer would most likely rinse it away.
Think of it as organic draino; the soil is the drain/pipe and the nutes and salt in the soil are the clog.
Exactly the issue I have. My perfectly healthy plants in 3 gallon containers turned to shit 2 days after flush. I flushed 3 gallon pots with 2 gallon of Sledhammer 2tsp/gallon. I also added 2tsp of Big Bloom to the last gallon.
The topmost leaves got brown rust all over them though the veins were still green. Some of the topmost leaves just brittled up and died. I am really ticked off. I was at 24 days of 12/12. I would never use Sledghammer again. I think it stays in the soil.
I mean I had perfect plants with nice colas going until this.
I sent FF an email gently asking what I did wrong. I got a reply that said the Fed Gov considers growing canibis illegal and gave me no help. WTF no sheet!... If it wasn't for us you would have ANY business FF.
I am now with Blue Planet organic nutes. Fuc* Fox Farm!