I’m using FF sledge hammer for the first time and am confused by the directions. It says “Perform a complete system flush every two weeks. Cycle your system for one hour and change reservoir water.”
What does this last sentence mean? Does it say to water with the sledge hammer mixture, wait an hour, then flush with clear water? Or something else?
That last sentence is for hydroponics.
What instructions are you reading?
I’m not 100% sure what that last sentence means. I flushed my system with sledgehammer by draining then pouring the flush mixture into each container the first flush.
Next I dipped each container into fresh sledgehammer a few times. Drained and added new a new fertilizer mix paying attention to proportions and checking ppm.
My sick plant took off and is doing well now.
I’m think the last sentence indicates to run your solution through your pump and system for an hour if you are using a circulating hydro system. I’m using what is called “deep water culture “ I probably should have soaked my system longer but is still turned out okay.
So what are your plants growing in 
Those directions are for hydroponic systems, there should be a different set for soil grows in containers and for coco-coir in containers.
The post says “outdoor grow” if your plants are in the ground outside then this product is useless.
It’s meant to “wash” or “flush” out any salt/nutrient build up in the root zone is all it does. Its really an unnecessary product that most grows just don’t spend the money on. If a container needs flushed every few weeks then to much nutrient is being used.
But let us know what you’re plants are growing in and exactly what FF nutrients you are useing and I’ll find you the right nutrient instructions for your set up, FF has several different ones.
Thanks for the feedback. I’m growing outdoors in 10 gal buckets.
The instructions are for “Flush” at the bottom of the instructions.
I’m growing in a mixture of FF Ocean Forest, Happy Frog, and Perlite.
I feed them with Big Bloom and Grow Big twice a week (no flowering yet, still veging). Most are very happy! 
Look up the soil feed schedule on the foxfarm website… think it’s like a teaspoon per gallon or something like that.
This is manufacturers instruction for soil and some other useful information.
All the products are not needed, the ones in green is all that’s really needed and the cal-mag listed in yellow possibly, i don’t believe there is much if any calcium at all in FF trio so a calmag supplement of any brand name would be a good idea to have on hand increase deficiency occurs.
Looks like is says flush with sledgehammer between week 4-5, 7-8, and 10-11.
Ok. Got it. You people are great!
