Sledgehammer flush

So im about to do a sledgehammer flush today and i was wondering if the water that i use to flush out the sledgehammer has to be ph’d or not

1 Like

I would for sure ph to your medium (soil, hydro, dwc) requirements otherwise your medium ph may fluctuate causing issues later down the road just my 2 cents


Bigcat is correct. Since you don’t water again after the flush, (per fox farms instructions) the liquid remains for a few days. So proper pH would be essential.
Copied from FF website…
When performing a SledgeHammer ® flush, we recommend using twice the volume of water as a normal feeding. For example, if you normally feed with two gallons of nutrient solution, you will want to perform a flush with four gallons of water mixed with SledgeHammer ® at a rate of 2 teaspoons per gallon of water. This will help remove excess nutrients from the growing medium. Once you have completed your flush, you will want to wait until the top two to three inches of your medium have dried before adding nutrients. This will help prevent issues with over watering.

1 Like

Been reading the forums and everyone says to flush it out dont leave the sledgehammer inside the medium…let it sit then hit it with twice the amount of water

When i flush i just use distilled water i mix sledgehammer in first gallon then flush that with straight one gallon of distilled water then mix my nutrients and cal mag at full dose with ph tap water and feed then let dry for 3 days

People are all over the place. If you want to rinse it out completely I don’t think it would do any harm.
Others have contacted Fox Farms about it and were told no final rinse is necessary.
So anything other that FF instructions is personal opinions. Might be good or not.