flushing salts?

Im needing to flush my 65 gallon smart pots.
I have dry spots and some salt.

I flushed with 5 gallons of water with a hose wand, not the drip system.

I'm afraid of "Over watering" but assuming 5 gallons is just fine to provide ample runoff with NO RISK?

I have read that you use 20% of the volume of the container when watering. so about 15 gals in your case.

did you mean you have 5 gallon smart pots ? or do you actually have 65 G pots ? anyways....if your plant is big enough and you have enough drainage you really cant over water it in one watering, its when you water too frequently that a larger plant will be affected by over watering....flush with the same amount of water as would fill the container...which if you have only 5 gallon pots you have already done this

A true flush is 3x the pot size... this meaning if you have 5 gallon pots, you will flush 15 gallons through them. Do 3 5 gallon flushes, approx 15 minutes apart.

better to give a last flush with diluted mild nutes since you washed all nutes away along with salt or toxic buildups, after that no nutes available for your plant to eat !