I have 2 autos, Northern Lights and OG Kush, growing in 5 gallon fabric pots in coco/perlite, fertigating with General Hydroponics Flora Trio, following a schedule from Cocoforcannabis.com. The two plants are in mid flower, and look great, but the runoff EC has been consistently high. The input has been in the range of EC 1100-1300, and the runoff is typically 1700-1800. I got it down to about 1500-1600 by flushing with a lot of 2x diluted nutes. But I’m wondering whether to do a flush with Flora Kleen, which is designed to flush out built up salts. Cocoforcannabis says to use the Flora Kleen if there are signs of nutrient lockout, but in my case there is not, the girls look great.
Should I just ignore the highish runoff EC, or do the Flora Kleen flush?
7 Likes
Water feed several rounds to liberal run off to bring the EC down , sounds like there’s a salt accumulation from previous feedings in the coco. Plants look great Growmie 
5 Likes
First are your meters calibrated? Mine lost calibration mid grow so I flushed when I didn’t need to which caused more problems for me.
That seems high to me especially for an auto I would lower that to around 800-900 and add another watering to the schedule
2 Likes
If your plants aren’t complaining don’t chase numbers. It’s will cause you more problems than it’s worth. Worry when your plants start showing burnt tips. 
3 Likes
I use the same nutes/medium. Are you watering to about 10% runoff? How frequently are you fertigating? I noticed increasing to at least 3 events decreased runoff ec. I have also flushed with flora kleen mid grow, no ill effects whatsoever. I did follow with zero tds water. At the time runnoff tds was 450 over input.
Looking good! And as others have said, dont obsess too much over numbers, follow what your girl tells you.
1 Like
I am watering enough to get a lot of runoff, but I’m trying to do it only once a day. In my last grow, I was fertigating twice a day in 3 gallon pots. This time, I used 5 gallon pots, hoping I could get by with once a day. I may need to go back to doing it twice a day.
For the 2 plants with runoff issues, I’ve been giving diluted nutes, EC 900 instead of the recommended 1250-1300. I still can’t get the runoff to be less than about 1500. But since the plants look very healthy, I’m reluctant to do a more extreme flush for now.
Once a day won’t be enough as they get bigger and go into flower they need more water. Water gets taken up easier than the salts so they build up in the soil, adding another watering should help balance that out.
That’s a photo in a 5 gallon air pot with coco/perlite I was watering 4 times a day
