Sledgehammer and feed concerns

I have been dealing with what appears to be a nutrient lockout situation using Fox Farm Trio nutrients over the last 5 weeks and not doing a flush. Trying to bring my PPM down from 1800, on my last watering I did not feed and only used calmag / Epsom salts, and it brought it down to 1300… I am planning on doing a sledgehammer flush tomorrow, but concerned that the plants would go almost 2 weeks without a feeding, since after the flush you don’t feed until next watering… Is this ok, or should I approach this differently?


There is no need to feed when your PPM is so high. PPM is a measure of the nutrient concentration in your soil.

The Trio is notorious for mineral salt buildups, which is what submarines your pH and creates a lockout. A flush needs to be all the way down to 300 to 400 PPM to be effective. Flush until it gets that low then give her a light feeding. Feed fully again once the soil has dried out and you can water again.


I appreciate the feedback. I have six plants in total that went thru the same feed, two are showing more signs of lockout than the others, a sample pic of the others below.

Would you flush all six, since they all had the same feedings, but may not showing signs yet? Is there a downside to flushing?

Only if your pH is out of line. What is your runoff pH on each?

Just giving my two cents, I personally do not flush until the plant indicates that it needs one(shows early signs of lockout). As far as feeding, my rule of thumb is typically i feed with the first watering after flush assuming ppms indicate it needs it. For example i l fushed my blue dream saturday because it showed signs of lockout, when i flushed it showed about 600 ppm. So when i water them next, they will also get nutes. Ive primaly used FF nutes during my grows. If ppms go below 1000 they get fed, and get water only until the ppms drop below that threshold again.