Minor issue that popped up last week, recommendations?

[Tyrith]

Problem:
34 Days in to flower, Slight tip burn & suspected nitrogen toxicity started showing up last week. Upon reducing the Nitrogen, a second issue started showing up on one of the two plants which I believe could be Calcium, Magnesium or even Iron? Unsure about how to deal with it as all my calmag's have 2-0-0 or 4-0-0 nitrogen in it. Epsom salts maybe? Have some kicking around but no idea how much to use. There is also some canoeing going on it up top, but I raised the light a few days ago because I suspect it's heat/light related with the temperature jump recently. 2nd plant seems fine with only excess Nitrogen showing. I guess this lady is a bit more sensitive?

Medium: Ocean Forest +20% Perlite

Feed & Supplements: Water-Feed rotation every second day, soil flushed & moved to bottled nutrients right before flower. Supplements have been Advanced Nutrients micro-grow-bloom (in that order) dosed at 13.3ml/Gallon up until very recently where I changed the micro to 50% -- 6.6ml/Gallon due to what I thought was nitrogen tox. Roughly 950-1150PPM, 77F, 6.5PH amended w/Baking soda cause the AN lineup seems to think perfect PH is 5.8-6.0. Measured w/plastic syringe & hand poured 1 quart each, 1.5G/every 2nd day.

Water source: Tap, 7.1-7.3pH, 175PPM. Watering run-off is 450-650PPM @ 6.2-6.5pH.

Strain: 2 Clones of Amherst Sour Diesel, Day 33-34 of flowering depending on pic.

Light: HLG 550

Climate: 4x4 tent, 78-84F during the day, the last few days the heat shot way up because it's been nice out. Humidity 40-50%. Night is 68-74F, same humidity. Trying to stablize this a bit but mother nature wants snow next week so who knows.

Additional Info: First post & lurker status, but have read a good chunk of infirmary posts, a couple of grows deep & have moved to keeping things as-simple-as-possible. I reduced the nitrogen last grow too early & ran in to a ton of issues, so I had been delaying it till I saw symptoms (day 26-28). Upon nitrogen reduction, one of the two plants started having the leaves show in the 3rd-4th pic? Could be a bunch of things but given the above data I figured I might get a seasoned recommendation rather than guessing at it till I spiral them in to doomsday right in time to harvest like my usual limps-over-the-finish line. This is my best grow so far, if anyone thinks they look 'too nice' for an infirmary post, just know that I've had much worse and am just trying to iron the last few bugs out. Cheers!

 

[Proph]

The odds of a nitrogen toxicity is slim... The nute burn seems to be the biggest issue right now. Over feeding can lead to a nutrient lock out if it continues. You could also have a ph issue since you are re-adjusting the ph after its mixed.. 5.8 is a good ph.. Ph of water/feeds rises naturally while it sits in the medium. So starting at say 5.8 gives much more room for the ph to rise without issues.. Starting at 6.5, the ph will rise to 7 or higher within a few hours. Your also using baking soda/ powder to move the ph. Baking soda, vinigar, lemon juice, etc are all very unstable and only stay stable for a few minutes, maybe an hour at most.. They all also raise your ppm levels quite a bit.. I would feed at 6-700 ppms and leave the ph alone after mixed. Let the mix/feeds sit for 30 mins or so before you take the final ph reading. I do not see anything that looks like a calcium or magnesium issue so I would cut the calmag out. Im sure its hurting more than its helping.

 

[Tyrith]

Thanks for the quick response. OK! I agree with you on the possibility on the overfeeding and have lowered the amount of Micro/Grow/Bloom to the below #'s which has the PPM close to your recommendation. Also, there was 0 usage of cal-mag & was merely mentioned as to what I thought it might be.

AN's recommends to use the Micro/Nitrogen at the same dose throughout the grow. Every grow (2) I've done using these amounts has resulted in Nitrogen toxicity towards the end, so the reduction on this has not changed. Please let me know if you feel I should dial this back up to match the grow/bloom at some point.

Feed & Supplements (Adjusted for this mornings feed): Advanced Nutrients micro-grow-bloom (in that order) - Micro at 5ml/G, Grow/Bloom at 10ml/G. Final reads before feed: 718PPM, 77F, 6.2ph. 2G/plant.

Will get some new pics up after their next watering. Thanks!

 

[Proph]

Thanks for the quick response. OK! I agree with you on the possibility on the overfeeding and have lowered the amount of Micro/Grow/Bloom to the below #'s which has the PPM close to your recommendation. Also, there was 0 usage of cal-mag & was merely mentioned as to what I thought it might be.

AN's recommends to use the Micro/Nitrogen at the same dose throughout the grow. Every grow (2) I've done using these amounts has resulted in Nitrogen toxicity towards the end, so the reduction on this has not changed. Please let me know if you feel I should dial this back up to match the grow/bloom at some point.

Feed & Supplements (Adjusted for this mornings feed): Advanced Nutrients micro-grow-bloom (in that order) - Micro at 5ml/G, Grow/Bloom at 10ml/G. Final reads before feed: 718PPM, 77F, 6.2ph. 2G/plant.

Will get some new pics up after their next watering. Thanks!

I think the feeds in general need to be dialed back... Not only do I think so, the plant thinks so as well.. The nute burn is saying it loud and clear. I don't grow plants based on charts and recommendations, so its hard to give advice sometimes. I will say this, back when I used bottled nutes, the highest ppm of a feed would be 7-800.. That was for 2 feeds, one week 7 and one week 8 of flower.. Every other feed was in the 5-700 range. Every plant is different.. As you grow your clones over and over, you will start to learn exactly what they like and don't like.