High EC run off, any recommendations?

Bbonez · Dec 18, 2020

Hello everyone, lots of great information on this site thank you.

I have 19 purple punch and (13) '91 kush in about 1 gallon pots 80/20 coco perlite. Under 2 1000W HPS, room is 10×10 but I'm only using half of it for my 1st grow. Temps have been around 70F and Humidity is low 40's.

Plants have been on 12/12 light cycle for 5.5 weeks now. During veg and first 5 weeks of flower I have been using GH Micro/Gro/Bloom w/ CalMag +. Keeping PPM around 940. RO water PH up to 5.9.

Tuesday I introduced MOAB @ 1tsp per 5 gallon and Hi-Brix Molasses @ 1TBSP per 5 Gallons, I reduced my base nutrients by 25% keeping my ppm at 940.

Everything is looking good to me but after reading on here I think I might have a problem with stacked nutrients in the medium. I water once a day at lights on 10 gallons with about 4 gallons of runoff. I checked the PPM of the runoff for the first time last night and I was at 1490 on the PP and 1690 on the Kush.

Plants look healthy with perhaps a tiny bit of burn on the tip of some fan leaves. I wouldn't have thought anything was wrong by looking at the plants. But I'm thinking tonight I'll mix up the same feed but add 5 gallons (reducing ppm by about a third) and flushing some of the old nutrients out.

TripsRabbit · Dec 19, 2020

Coco always has a high runoff, I never check mine.

Bbonez · Dec 19, 2020

I did as planned last night, mixed up 15 gallons and it came out to 610PPM. I watered as usual once and the runoff was the same as the day before. After a half hour I watered once more and this time the runoff was 1190 PPM. Thats 250PPM higher than my normal 940 water.

Do I go back to my standard 940 PPM 10 gallon schedule tonight? Or do another 610 (2 times) flush?

Bbonez · Dec 20, 2020

Went back to my normal 940 PPM 10 gallon watering and the runoff was 1120, seems like I'm back in the optimal range.

Madmax · Dec 20, 2020

Id say you will have to water multible times in those small pots to keep your ppm in check..
This is up your alley Aqua @Aqua Man

Aqua Man · Dec 20, 2020

Bbonez said:
Hello everyone, lots of great information on this site thank you.

I have 19 purple punch and (13) '91 kush in about 1 gallon pots 80/20 coco perlite. Under 2 1000W HPS, room is 10×10 but I'm only using half of it for my 1st grow. Temps have been around 70F and Humidity is low 40's.

Plants have been on 12/12 light cycle for 5.5 weeks now. During veg and first 5 weeks of flower I have been using GH Micro/Gro/Bloom w/ CalMag +. Keeping PPM around 940. RO water PH up to 5.9.

Tuesday I introduced MOAB @ 1tsp per 5 gallon and Hi-Brix Molasses @ 1TBSP per 5 Gallons, I reduced my base nutrients by 25% keeping my ppm at 940.

Everything is looking good to me but after reading on here I think I might have a problem with stacked nutrients in the medium. I water once a day at lights on 10 gallons with about 4 gallons of runoff. I checked the PPM of the runoff for the first time last night and I was at 1490 on the PP and 1690 on the Kush.

Plants look healthy with perhaps a tiny bit of burn on the tip of some fan leaves. I wouldn't have thought anything was wrong by looking at the plants. But I'm thinking tonight I'll mix up the same feed but add 5 gallons (reducing ppm by about a third) and flushing some of the old nutrients out.

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Ok so whats happening is this i assume... bit you can check to verify yourself.

You are flushing tons daily with nutrients which is whats keeping you from having issues major issues.

So when you feed test the very last bit of runoff and I bet its fairly close to what your putting in since feeding such a high volume.

Then that night or the next day catch the first bit of runoff and test. I'm thinking the ppm will be very high like you found it before.

As the plants are drinking a lot, add any evaporation and the nutrients are becoming more concentrated in the media as water is removed. So it's likely your ppm is pretty decent right after feeding and the rises through the day as it dries.

I am also in 1 gal pots but feeding 10 x a day at 250ml per event. Much less in total but much more constant so the ppm, ph and moisture level stay nice and stable.

I understand you probably are hand feeding so 10x a day is not doable but as many times a day as is possible is what I would recommend. Then if going forward sticking to 1 gal I would invest in a fertigation system.

I recently did a thread that may interest you.

HOW TO WATER COCO FOR BEST RESULTS.

Ok writing this cause i see this issue often and rather have a thread to link than explain this each time. This is not my work but a collection of info from many members here and I have put into practice myself. So first off COCO is NOT soil. For best results we want to keep it saturated...

www.thcfarmer.com