Cannot seem to avoid Nitrogen Toxicity?

[ballplayer 2]

Hi all, hopefully there will be some folks here familiar/experienced with dealing with Nitrogen toxicity.

I have been practicing my growing skills on tomatoes and peppers indoors for about the last year or so, pretty successfully. However, with cannabis I have been having problems with what I believe to be Nitrogen toxicity from mid-veg into flower.

I have been planting in a 50-50 mix of either Biobizz allmix/FFOF and Sunshine Mix#4. I have been waiting a pretty long time before adding any additional liquid ferts, usually about 3-4 weeks. My runoff 3 weeks into flower came out at 1120-1170 on a 640 scale, on two different plants. Probably a touch high for this point, and higher than I had anticipated. Guessing too much of that content was N. I have been using liquid pH drops to gauge my pH levels, aiming for yellow-green (6.5).

I am pretty certain it is Nitrogen Toxicity. My leaves are really dark green. I have some edge, small browning/burning. That condition seems to be exacerbated by a hot/dry setup, since moving under my air cooled system the burning has mostly subsided. After a plain water watering (getting about 32 ounces runoff from a 3.5 gallon pot) some of the bottom leaves showed some mild tip-burn, where there previously was not. Some of the top leaves on the crown of the plant are a bit misshapen, not terrible, but not totally perfectly shapen, kinda skinny-ish. The "N" claw is NOT present. Flowering progress has slowed. No other deficiences present.

I have a few questions for those interested in helping me. What is the best way to avoid too much N when using prefertilized soils like Biobizz Allmix or Fox Farm Ocean Forest?

Should I aim for greater runoff after the first couple of waterings after transplanting into these hot soils?

At this point in flowering how long would you expect this toxicity take to subside? Will I be able to solve this issue through a couple of plain waterings before resuming a feed regimen? OR will I need to go full-on flush (I'd rather not if possible). Like I said flower development has slowed, Claw is NOT present, Calcium is not being antagonized yet.

Please feel free to expound upon any additional advice/experience you have with this issue.

Thank you for your time and experience,

BP

 

[joe fresh]

Should I aim for greater runoff after the first couple of waterings after transplanting into these hot soils?

no i think you should wait longer before feeding your plants, and when you do feed them feed less

 

[señorsloth]

your goal should be to use as little nutrients as possible to keep your plants healthy. what kind of fertilizer are you using? how much are you using?

for the record, the whole "wait 3 weeks" to fertilize when using preferted soils like fox farm ocean forest, only applies if you transplant a decent sized plant into it. a small plant, a clone, or a seedling will take a lot longer to use up the nutrients, for instance a seedling in a 3 gallon pot of ocean forest could probably go 2 months without getting it's first fertilizer. when going from seed, what i do is wait till the cotyledons start to yellow before i give my first feeding, and then i never go above half strength!

right now i'm using maxibloom(lucas formula) at a rate of half a tsp per gallon(half strength), for 2 waterings and then a watering of plain water. adding more ferts than your plant needs to stay lush will not show much increase in yield, but will quickly build up salts in your soil and mess with your ph a lot, of course you know already that it will eventually cause necrosis and stunted growth. Additionally, having more nutrients in your soil than you need, even if the plant can handle it, just makes it harder to flush out at the end.

i have found that most strains i have tried don't like full strength nutrients, only a few have been able to handle it, also only one strain i have tried so far like 1/4 strength nutrients(og), however, ALL my strains like 1/2 strength, so it's useful in that i can mix one batch of nutrients and use it on all my plants, also i grow in beds, so it makes my life a lot easier not having to worry about one plant having a deficiency while all the others sharing the soil around it don't