High ppm runoff after flush

my ppm was 896 when I watered, and run off was ~1300, I flushed and tested that water and it was reading in the 4000+ range. is this because I used so much more water to flush than I would w normal watering/feeding? would a reading on the runoff of the next water cycle be more accurate?
I JUST started reading ppm so maybe I’m freaking out or missing something
any tips greatly appreciated, thanks!

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You know I’m right there with you on trying to read and understand the ppm. You gotta start logging every time you water. I started a log but kinda gave up on it because I’m using a supersoil in ffhf and that’s going to show you a higher run off. I had the same readings you had. I don’t think it’s bad until you start to notice a change in your readings. But again. I’m still trying to get it down. Hope this helps and when you figure it out do fill me in please.

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@GrassMan420 ive been logging all of my nutes and ph up to this point and just started reading ppm today, when I measured my nutes like I normally do, the ppm was right around where it should be, I was very pleased w that, but when I checked my runoff it was a bit higher, which wasn’t a total shock, it’s when I measured the ppm after the flush Is what freaked me out and what I’m really trying to figure out

How big of pots? What ppm have you been feeding with? What is the growing media in pots? What was ppm of your flush water? Ans how much wate4 did you flush with?

It sounds like maybe you just didn’t flush enough, but i would like to eliminate the other possibilities.

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Welcome to the community ! what does the plant look like. I don’t quite understand why the flush with PPM Run off 1300 . :v::+1:


It was my understanding that ppm runoff should be lower than the water/nutes going in, I just got a tds meter so maybe I panicked and jumped the gun w the flush, I don’t know.

I use fox farm ocean soil in 3 gl smart pots. fox farm trio at half strength(week 8 of ff schedule), 1 ts calmag per gallon in between feedings. I use tap water left to sit for 48hr, always brought to a ph of 6.5 for feed and water. I water until I see a bit of run off, usually around 1500-2000ml.
I flushed w new jugs of spring water that measured 0008ppm

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I flushed w 2 gallons on each plant.
Checked on the plants this morning, they look just a little wilty, I’m assuming that’s just from the extra water and I was planning to just let them dry out before the next water.
It was also my plan to flip them to 12/12 this week, but maybe I should wait?

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  • What strain, Seed bank, or bag seed
  • Method: Soil w/salt, Organic soil, Hydroponics, Aquaponics, KNF
  • Vessels: Pots, Grow beds, Buckets, Troths
  • PH of Water, Solution, runoff (if Applicable)
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*super skunk fem(ilgm)

  • Ocean forest soil
  • 3 gal smart pots
    *PH 6.5, runoff ph 6(avg of both plants)
  • PPM 896, runoff 1300(avg of both) FF trio half strength (week 8)
  • Indoor tent 2x3
  • Vipraspectra p1000 x2 12” above at 50%
    550 umol taken on photon app
  • Temps: thermometer broke, but it was ~70/60
  • Humidity; ~60%
  • Ventilation system; ac infinity cloud line s4
  • Humidifier plugged to controller at 60%
  • Co2; , No

I mix 1ts calmag in 1 gl ph’d water in between feedings, around 2000ml of water

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Not bad IMO, now the 4000+ range is high AF. My guess is your ppm was way too high in the flush water going in or you need more than 2 gallons to flush it completely. I believe FF wants you to use Sledgehammer to flush with. Maybe try that. I grow in coco with Jack’s so I don’t check ppm anymore. If you haven’t followed the FF flush schedule, you very well may be nutelocked at this point. I would for sure get this fixed before flipping to flower.

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I’ll get a FF flush today and try that out
I have not been paying attention to ppm up until this point, and looking at the FF feeding schedule again, I feel like I might have been fucking up, I have only been looking at nute amounts and feeding each week, but looking more at the chart, nutes flip to 12/12 and adds tiger bloom at week 5 w flowering levels ppm, I’m on week 8 and still on 18/6
Should I flush w the FF sledgehammer then maybe go back a few weeks on the schedule until I’m ready to flip to 12/12?

If you don’t flower continue week 4 veg until you do. When you flower that’ll be week 5

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So I’m planning on another flush w FF sledgehammer when the soil dries out, for my next move, would it make more sense to to flip to 12/12 and start the schedule again at week 5, or let them sit in the veg stage for a week or few? I repotted the seeding in their 3gl pots a little over 60 days ago

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Yes if you’re ready

Flushed w 2ts sledgehammer in 1 g of water per plant ph6.5, run off went down to the 500 range w a ph of 6, no nutes added after. Here is the next day, pulled off a few sad leaves

Planning on moving back to week 5 of the FF schedule and flipping to 12/12 onto normal feed day, which will be 3/11


Looks good I’m watching. Re nute


Quick update, soil was dry so I fed a day early ahead of my usual schedule, back to week 5 FF, I mixed the nutes, in 1gl of water at ppm about 1050, didn’t see any runoff so I mixed the exact same amount giving each plant a gallon(does that make total ppm 2100? then?), runoff was 1474 on one, and 1042 on the other
Does this seem right?

Also planning on taking advise from the grow guide and doing the 36hr lights off tonight before they turn back on to 12/12


Sounds good :ok_hand:t5:


Checked on the tent after 36 hr dark period to flip and they look fantastic, obvious new growth and leaves are at attention, humidity is a bit high, but figured that would happen,