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

[johnjoemurphy]

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!

[Minzone]

From the pictures looks like a calcium/magnesium difficiency.

 

I've had a similar issue running the same nute mix seems canna nutes may be lacking it entirely or just not in high enough concentration for the particular plant we are trying to grow.

 

After using a mid strength dose of cal mag I didn't have any more issues like the above pics.

 

You will be able to get it where ever you got your other nutes from.

 

I wouldn't use h202 if I where you fuck spraying that shit on your buds.

 

I had gnats as well.do you run an intake ? Seems where my intake runs from there where a lot of gnats comming through (squashed on screen) I countered this by using a stocking over my intake duct so they couldn't get sucked in.

 

I just let them go until the end of the grow quality or growth wasn't effected.

 

If you want to control them put some fly traps in the grow room.

 

At the end I chucked roots (the lavae live at the root base) and net pot and sealed in bag then in bin and left the grow room without any organic matter the gnats like for like 1 week and haven't had them back since.

 

Just my 2 cents good luck

 

Edit : I didn't make it clear to use medium dose cal mag from now on start to finish.

By medium what I mean is my bottle stated to use 5-8 ml per litre I went with around 6.

Edited August 11, 2014 by Minzone

[Frank Reynolds]

Cal/mag issues will show on new growth not on old growth

[Minzone]

The spotted browning effect that from the looks of it is effecting the whole plant is what I'm reffering too , the yellowing leaves seem to be old fan leafs and going yellow naturally do to lack of nitrogen because of low nitrogen in flowering nutes , plants will use the nitrogen from older leafs for new growth.

[Frank Reynolds]

Looks like a general n def, it def isn't cal as I have experience with that and yellowing will start on new growth close to the petiole and work its way out

[billygoat]

Look fine to me

[mastertig]

maybe a pk overdose?

[johnjoemurphy]

From the pictures looks like a calcium/magnesium difficiency.

 

I've had a similar issue running the same nute mix seems canna nutes may be lacking it entirely or just not in high enough concentration for the particular plant we are trying to grow.

 

After using a mid strength dose of cal mag I didn't have any more issues like the above pics.

 

You will be able to get it where ever you got your other nutes from.

 

I wouldn't use h202 if I where you fuck spraying that shit on your buds.

 

I had gnats as well.do you run an intake ? Seems where my intake runs from there where a lot of gnats comming through (squashed on screen) I countered this by using a stocking over my intake duct so they couldn't get sucked in.

 

I just let them go until the end of the grow quality or growth wasn't effected.

 

If you want to control them put some fly traps in the grow room.

 

At the end I chucked roots (the lavae live at the root base) and net pot and sealed in bag then in bin and left the grow room without any organic matter the gnats like for like 1 week and haven't had them back since.

 

Just my 2 cents good luck

 

Edit : I didn't make it clear to use medium dose cal mag from now on start to finish.

By medium what I mean is my bottle stated to use 5-8 ml per litre I went with around 6.

Thanks mate I tried some epsom salts today. I'll get a bit of the cal/mag during the week.

 

I'll try that trick with the intake, did it affect the airflow at all? 

 

I was hoping to reuse the coco its brand new, I usually get 3 grows from my coco. Any way to get rid of the thrips larva in the coco once I harvest this crop?

maybe a pk overdose?

I was thinking this also as I use it a lot more than they recommend but i've never had any issues before.

[mastertig]

strains respond in diff ways to other strains

ive noticed pk can prolong the maturity of the plants as well

maybe next time try a  lower dose if u got clones of these

see how they respond

[johnjoemurphy]

Thanks for the help lads.

So ph meter still didnt come so got a liquid tester from pet shop, PH is at around 6 and I'm assuming has been all along as I tested under my normal feed routine.

The plants that are yellowing all started at the bottom and worked its way up, Also a lot of them look very close to finish when I looked under a microscope one of the cracks is starting to shoe brown trichromes and the othe cracks and thc bombs are almost all milky. the blue dream & pinapple have yellowing but not to the degree od the other too There is no yellowing at all in the gigabud, delahaze or NL X Skunk. Maybe the fact i have short flower and long flower all on the same schedule means that I under or over fed the shorter flower plants?

Hopefully the meter will come on Monday as the test I got isnt the most exact but at least I know I'm not a million miles out with the ph. I know that 5.8 is better for hydro of course and ill bring it down to that once i have the meter.