There was probably some issue with your buffering treatment. Flush them with your 3 mS/cm solution until your input/runoff EC values match and you’ll likely solve the problem.
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Add vegetables, ammonium sulfate Thanks for the knowledge, if during flowering we can still add ammonia sulfate or not. Thanks
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That’s my question also. Can I safely run a mix that’s 80/20 NO3/NH4 in transition and pre flower? How about all the way through flower? Anyone please feel free to chime in.
I could be off but if I’m not mistaken high Nh4 can cause ammonium toxicity but as long as your not supplying 30%+ you should be good. I have a study in my notes that talks about this and various ratios between no3/nh4 if you want it.
Also higher temps in your room will have your plants using more sugars and less oxygen in the root zone will have ammonium building up as it will not be able to convert to nitrate and high ratio of nitrate will increase ph in the root zone.
Some of the science guys will jump in I’m sure but I don’t think it’s as easy as just set my nitrogen ratio and forget it. Room temp, leaf temp, substrate temp, and microbial activity will play a role.
But to answer your original question I don’t see why you would not be able to run the ratio above. Assuming your coco is airy and your on top of drybacks I don’t think you would have issue.
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Thanks for the response. I’m basing my ratio off of an article from Science in Hydroponics, that suggests in order to balance root zone pH, a ratio of 80/20 No3:NH4 is suitable. I’ve read a few threads on some forums stating to much NH4 in flower can cause plants to revert back to vegetative growth. Definitely want to avoid this and any ammonium toxicity. Thanks for the clarification.
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fpls-13-830224 (1).pdf (5.1 MB)
You’ll probably like this article here then. Good read.
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Love this kind of stuff! Thanks for the link.
Having an ammonium/nitrate ratio at 20:80 or even 30:70 can be very beneficial for growth and pH control up to around week 2 of flower. After that you do need to lower the ammonium below 10%, otherwise you can lower the quality of your flower. The pH drifts in the media will tend to reverse when flower is growing, so it is also counter productive to have high ammonium in media after week 2 (it might lead to overacidification of the media and micro nutrient toxicity issues).
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Thank you @danielfp. I’ve only been running the new mix for about a week on plants in veg and plants that are at 21 days since since reducing the light schedule to 12/12. The media runoff pH continues to climb, almost at 8.0 pH. I will reduce the ammonium when I start making my flower mix. Thank you for the help Dr Dan! I truly appreciate it!
No problem, happy to help! You might want to do an Fe+Mn foliar spray, because at a pH of 8 in the media you are almost certainly guaranteed a micronutrient problem. You can also add some ammonium sulfate to your current mix (as I mentioned previously on this thread), to try to alleviate the issue.
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Thanks again @danielfp. I’m not noticing any micro nutrient deficiencies at the moment but, I might be missing them to my un trained eye. What I am noticing is purple streaks on the main meristem, and purple leaf petioles with the underside leaf veins also turning purple.
If you’re feeding at 5-5.5, you’re probably giving them some chance for micronutrient uptake and delaying the issue. But if runoff is at 8, those issues will develop if the situation is not normalized. Watch for lighter green color in new leaves as a sign of this developing.
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For anyone reading. Maybe some one can help me out. I’m having an issue that when my lights go out, for some reason, the plants in the flower tent, and in the veg tent start to smell overwhelmingly. The oder goes right through the charcoal filters for some reason and can be smelled throughout the house! Someone told me it’s due to the plants stomata being opened. What is causing this, does it mean something is wrong nutritionally, or environmentally and how can I correct the situation? Thanks in advance everyone.
Just wanted to bump this and see if anyone had an answer.
I thought it was this but my humidity is monitored 24 hours a day. At lights out it was 55 percent. It did not rise and dropped to 52 percent with in 4 minutes of the lights being out. The smell started almost immediately after the lights went out. I’d like to add that I sometimes have the carbon fans completely off in the flower tent and no smell ever escapes. It’s only immediately after the lights go out. 
I’m not sure how old your carbon filters are, but that may be an issue. They definitely don’t last forever and your mileage will vary.
For instance, my lady owns a salon and we had a nail tech in there. We were changing the carbon filter almost monthly but once we got her up out of there the filters were lasting much longer.
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It’s brand new. First run with it actually.
Hey guys! What do you recommend for Ace seeds Ethiopian landrace? My last run was Hogland 50% diluted. 1 EC. Dubi wrote that is maximum in Coco coir. 1.2 maybe for the tight Led… So…
I do something like this now… 56-30-112-120-10-45? SOP for K.
4 weeks 11/13.
Did you take the time to read through this whole thread?
I believe your question would be answered. Also there are multiple other thread discussing nutrient profiles. Dig a little and you’ll find some gems.