New grow trying to understand fox farm nutes

Hey everyone I had a question on understanding the salt bulid up and “flushing” the soil? What is salt bulid and does it always happen? I have been trying to read the other post but I just get confused. When you flush what are the signs you are looking and if you flush water thought the soil does it open opportunities for root rot to occur?

1 Like

So I don’t know about fox farms line up but I do no about “salts”. It refers to the fact that the nutrients used in the fertilizer is pure isolate forms.
Any mineral in pure isolated firm is basically a salt. .

What happens is over time the pot drys and the minerals crystallize in the soil and literally build up on the roots and chock them out.

Flushing every so often with lots of water. Helps wash the “salt” build up away so the can continue to feed.


I use general hydroponics trio, and rarely have to flush but I have alot of run off each time I water .
It can be a little intimidating but it’s not near as complicated to do as it seems. It can be extremely tricky to grasp andcim not the best at explaining it I don’t think…
But I have seen Fox farm has a sheet that gives step by step what to do at each week along the way.
I think if you follow it, by the time you get half way through the grow, you will have it down pat.

I will say that I have heard that it isn’t a good idea to not flush with Fox farms suggested times or it builds up quickly… maybe their line up is pretty strong :man_shrugging:

Is it a build up of salts due to chelates?
is it a build up of non absorbed nutrients from over fertilization? I don’t truly know.

I stopped using fox farms after a few grows, but certainly learned how essential regular flushes were when using fox farms nutes.

I’m not bashing fox farms. It will grow decent weed if used properly. I recommend it to most people just starting out. I just never invested the time to investigate…

They want you to hurry up and use the bottle up so you can buy more. So they suggest high ppm doses that need flushing because of what the above poster already stated, build ups. I use fox farm nutes but on my own regiment

1 Like

This should not happen provided adequate ventilation is provided and the runoff is removed. It is also important to have a good draining pot.
This is my set up for dealing with runoff

The accumulation of salts can often be seen on the sides of black fabric pots as a white residue. The best way to know it is occurring is by regular testing the runoff’s pH & PPM. As salt builds up the soil’s pH will gradually decrease. When I used soil and fox farm trio the benchmark was a .5 decrease in PH from where I started. That is why having at least 10% runoff volume is recommended when using FF nutrients. Up to 20% can be done as well. Especially if you want to do some preventative flushing.


So idle every water you want give them more than the actually 5 gal I’m assuming?