Hi all,
Ive been having this little problem with 2 of the strains I've been working with.
For some reason, the top colas and leaves are showing some signs of malnutrition. This happened to me once before in veg, but then I flushed everything out and restarted its feeding program, which cured it. But the problem now is that this is in flower mode, dont really have much time to work with here.
First, the leaves start to get yellow or orange spots... simlilar to stiples from mites, but much bigger and noticeable.. then the spots start turning darker...eventually, the spots become bigger and the leaves start getting holes in those spots... this typically happens from the top of the plant on down. it gets to a point where the whole leaf or cola is devoured, making it look like a catepillar or some type of insect is having a feast on my plants, but its not, its something with the feeding program. The medium I used is coco, but some other plants are fox farm soil and they both react the same..
This only happens to 2 of the 8 strains I've done.. been doing this about 3 years, and this is the only problem I cannot remedy. Once this happens, I usually flush everything out and restart its regular feeding schedule. this method works, but its only good in veg mode because it has time to heal. during flower, its kinda hard.
pH of medium is about 6.5 the lowest and usually 7.0 on avg. Only thing I can think of is chlorine because sometimes I dont sit the water out a couple days before watering. In Flower, its a mandatory i let the chlorine settle, but sometimes in veg i dont. I dont know the effects of too much cholrine in the water because I havent really encountered or seen anybody encounter that problem yet.
Ive tried researching online, cant seem to find the same problem online.
I would suggest the pH is getting too high if it's hitting 7.0. I personally don't think it's chlorine, I've never once seen that as a symptom in any type of plant where chlorinated water is being used. Of course, if you eliminate the chlorine (use something like sodium thiosulfate, aquarium dechlorinator is based on this chemical) then you've eliminated that as a possible source of the problem.
The coco pH needs to be kept in a much lower range than that of soil, too. Coco needs to be 5.8-6.2, whereas ideal soil range is 6.5-6.8. Start there.
It maybe pH but IMO the mofos look nute burned, trust me I just had that happen a couple crops back, I grow in an enriched organic soilmix that I've been using awhile now, and I was doing fine till I got lazy and didn't brew my own tea and decided to use FF Big Bloom as a replacement, over night my plants went to shit looking exactly like yours, I almost though it was some type of disease/virus/pests but I knew it had to be the ferts, that's the only thing I had done different. All I did was washed them out with 2.5 gallons of water per 5 gallon pot, in a couple days things were looking better but the f'd up leaves never recovered I removed them after the new growth took off.
Sea will probably get back to you in the mornings, as she does, but even before I read your post about the 7.0, I was going to jump on the pH bandwagon. For sure pH. You keep referring to the "pH of the medium." How are you checking the pH of your water and nutes? I would definitely flush the coco with some pH adjusted water at 5.8-6.2, preferably the lower end of that if it's been near 7.
Ph being off would definately send them into stress. I'm going to go a step further and say that its also caused a lockout or buildup of salts. I know FF soil can really build up unwanted nutes I really dislike the stuff now. For indoors im switching fully to Sunshine Advanced #4 its a lot cheaper and easier to use then my half bug infested FF soil. My local store did say FF was still creating another "super mix" I guess we'll see.