Nute burn?

Hey guys, I transplanted these a couple of weeks ago from DWC to coco coir, they didn't look like they would make it before. They are 5 weeks old since they sprouted. Since I've transplanted them, they've been growing A LOT and seemed quite happy. Recently the tips began to yellow on the new growth (more so on the Girl Scout cookies, but also the blueberry). The GSC seems to be getting worse, while the blueberry seems to have recovered.

I should have probably skipped watering yesterday, but I wanted to get them some fresh pH'd water in case it is burn. But it looks like they may be slightly overwatered. I'm still trying to figure out when exactly to water them in Coco.

Medium: Coco Coir
pH: 5.8
ppm: 473 (GSC, more sativa looking) - 600 (blueberry, bushier indica)
Temp: 65 degrees at night, 75 degrees lights on
Lights: 4 x Cree 3590 COB LED
Humidity: 50-65%


I've read that full veg should be about 450-700ppm, I'm assuming this may be WITH the ppm of my tap water. I use the GH micro/bloom/grow and supplement with calmag. As I went to double check the ppm, I do realize the pH got a bit out of whack in my premade nute buckets, they're sitting at 6.3-6.4. Maybe nute lockout? I imagine if it changed in the buckets, it had to have changed in the medium.

Edit: I did see a gnat fly by as I was watering them yesterday, since then I've thoroughly cleaned the room and sprayed the soil down with neem oil. I have some yellow stickies on the way.

Sorry, I forgot to add pics

Yes, include tap water EC in total measurement.

If you are trying to correct an issue in coco, mix a new solution and water with this. Coco has very little CEC and relies on the root zone solution.

Always allow the nutrient solution to settle to a stable pH before watering.

Gnatrol would be preferable to neem oil. Oil in the rootzone is not advised by anyone but neem fanatics.

Thank you for the good recommendations! That may be where my problem lies, I usually mix a nute solution then use it immediately. Since I'm using 5 gal pots, I don't have to water often, but I'm guessing in that time the pH is rising and causing lock out. I've seen a few pictures when I was searching for an answer, it almost looks like a zinc deficiency?

Like said I would do a good flush with fresh mix and it should help with the imbalance going on, maybe a imbalance in the uptake from one medium to another and a certain strain or plant is more sensitive or that pot inparticular has a local imbalance, either way flushing and replenishing with a lower strength, ph'ed mix is what i would do and flush a gallon or 2 at least for 5 gal pot, i would worry about pests after new growth starts proper myself. If growing strong a guy can go way over your ppm parameters so i would say thats not your issue

Still can't see any image.

Toss a small aquarium pump in. A few elbows will make it a tiny mixing pump. Usually only takes a few minutes.

If your not using a water purifier/and or softener you need to let it sit 24 hours before watering. Id add nutes first then wait 24 hours and check. Are you hand watering? res? A little info might help

Also did you flush your coco before transplanting into it? What kind of coco are you using. A lot of coco companies claim to have theirs pre-rinsed and still has a lot of natural salt build up in it. I find that giving my coco a good flush before use has worked really good. I use phd water and sometimes add florakleen

Sorry for the lack of details, I'm growing in Coco coir, 5 gallon smart/fabric pots. Hand watering and drain to waste. I'm using Cyco coco coir that comes with perlite added. I did not flush it when I got it (rookie mistake, first grow), but they seemed to love the Coco. At first I was going to toss them, as I started in DWC and they did not look like they were going to make it. They were stunted and short with very twisted growth. After transplanting them they did great until this incident.

I did let the water/nutes sit 24 hours before flushing them a few days ago, and the new growth is starting to look much better. I just haven't seen nute burn first hand, so I'm always changing the ppm thinking its burn or a deficiency. They're about a foot tall now (when tied down for lst), and I'm thinking about switching to 12/12. The blueberry has so many growth tips nice and level, but the entire plant is very short and bushy with short node spacing. I've actually had to tie fan leaves off a bit to let the lower growth tips get light. May have to add another fan to prevent bud rot/powdery mildew later on. It's almost impossible to keep all th leaves from stacking/touching each other

I was thinking about pruning, but I hear a lot of people saying that you should not prune on your first grow. For my sake, I wouldn't prune any fan leaves (incase I screw up in flowering), but maybe really low growth tips that don't stand a chance

don't do any pruning until later in flower part of the plants nutrient intake, breathing, etc. goes through the leaves