Day 38 and VERY yellow leaves. Green Crack, Blue Dream, THC Bomb...

Okay so brief history on the grow so far.



I am on day 38 since the I flipped to 12/12.



Set up: I am growing using 70/30 coco/perlite in Autopots. 2 x DR240w tents with 2 x 600w HPS in vertical parabolic reflectors. Both tents have their own reservoir but they are on the same schedule.



Food: I've been using Canna nutes at the regular feed amount per their schedule, along with Rhizotonic & Cannazym. I also use Canna PK 13/14 However Canna recommend only to use this for one week. In all of my previous grows I use usually 2 weeks before and 2 weeks after their suggested time starting at 1/3 strength then 2/3 with full does in the middle. I've never had any issues feeding this way before.



Climate: It has been fine around 75F for the most part dipping to 65F at lights off, only have one sensor in the tent placed right under the bulb so cant say for sure that those temps hold true all over the tent. Sensor in my 2nd tent also read the same though. I'll be honest it is unusual for me to have temps like this I almost always have issues with high temps in the 85F-90F range sometimes during lights on, but not this grow even though we have had some of the warmest weather in years.



Humidity: This is an issue always above 60% going as high as 75+% at times. Nothing I can do its very humid and damp where I live and my are is piped in from outside. Every grow is like this.



Pests: I do have a bad white fly (or maybe gnat) infestation at the moment. I have some H2O2 coming which I will be using as a foliar spray to try and get rid. Fan leaves are fairly riddles with tiny white marks where the fuckers have been sucking on the leaves. I was not able to get the H2O2 before now, it should be here Monday/Tue.



Other Factors: I'm embarrassed to admit I have not PH'd my water in a long long time. When I started growing I had a formula for amount of PH- that was needed per litre which worked for me up until now. My PH meter is broken so I cannot check if it is a PH issue but I have ordered a new one it should be here Wed/Thur. Also I have a PPM meter which I never used. It is one of these cheap ebay yokes.



According to Canna my total EC should be 2.4 this week I took a reading of 1290 from Tank A and a reading of 1150 from Tank B 2 nights ago when I took the photos below. Now I'm not sure how to convert but by the looks of it I am well below 2.4 no matter what conversion I use on this chart



I brought the feeding up to Cannas High schedule and will be returning to the grow tomorrow night hopefully it is just a lack of nutes but I'm worried it may be lock out due to PH or some deficiency. Maybe even the gnats/whiteflies (im not sure what they are to be honest, i think gnats)



Anyway here are some photos of the Green Crack, Blue Dream & THC Bomb. They are all new seeds but I have grown these strains before and they are 8 weekers. This is the tent that is being fed by the tank with the lower EC. In the other tent i have the same issue but not to the same extent, the strains in the other tent are all meant to be shorter flower than this tent (Gigabud, Delahaze, Pineapple express, Northern Lights x Skunk)



Anyway here are the photos I'd appreciate any help or ideas that you might have. Thanks!

Most of the pics don't look too bad. But the first two look pretty bad. If you're feeding a decent veg nute, with a good amount of N, perhaps the ph is off? It's pretty normal at this point to get some yellow fans. There may be a lock out problem in the first pics?

Good Luck and we'll bump you back to the top

They look like they are starving .

when you use a pk booster, you should remember to reduce your base nutes. in flower, rh should be below 50%. i don't understand how you have hydrogen peroxide coming... you can't go get some on your own? do you live in hooterville??? forget what your meters tell you, what are the plants telling you? so you're growing hydro without adjusting ph??? amazing...

With the amount of nutes you're using there is no reason these plants shouldnt be completely green, maybe even too green at 2.4 ec. Your PH is fucked dude, hands down. I'm going to guess 5 or lower. It must have been pretty low for awhile now for your plants to look that hungry for nitrogen.

Silky Shagsalot said:

when you use a pk booster, you should remember to reduce your base nutes. in flower, rh should be below 50%. i don't understand how you have hydrogen peroxide coming... you can't go get some on your own? do you live in hooterville??? forget what your meters tell you, what are the plants telling you? so you're growing hydro without adjusting ph??? amazing...

Click to expand...

Where I live it can't be got my friend, should be here tomorrow though.

I was watching it at the start but after a few months of always dosing the same exact amount of PH- to get teh right PH I just stopped checking PH. I've not had any issues in the last year + until now. Every other grow has been fine with exactly the same schedule, nothing has changed.

I wonder if its possible that they are treating the tap water differently now and the original PH has changed.

Either way though I should have been monitoring it. Just goes to show that you can't get complacent.

You may be able to get an analysis of your local water. Google your municipality of town and "water analysis" or "water quality".
pH may not be a problem as some nutrients are pH buffered to right around 6. But I don't have experience with the Canna line.
Definitely test the water before and after you mix the nutes though. I use GH and only adjust my water when I'm not using nutes.
There are cheap test kick available just to make sure its not way too high or low, not precise but better than you can do without it. Both water and soil kits are available for a few bucks each.
If the growth is good but there is yellow leaves it may be a deficiency. I associate the green-yellow scale of leaves with nitrogen. Dark green is an abundance and lighter, or yellow leaves have a deficiency. I think sulfur has similar signs but I haven't had to deal with that.
Hope it helps

pH is the problem as the plants will not uptake the nutrients if the PH range is off. And here's how I can tell it is your PH, you have the PH curl that I got when I first started hydro without a PH pen look at picture 7 I believe the tip of your leafs are curled that's from PH being off.

Secondly there is no telling if your plant will like all the chemicals your local water supplier dumps in the water to make it "safe" for drinking. I use R/O water and would NEVER go back to my towns water supply even though we have really good quality water here.