First off, thanks in advance for any thoughts/ideas/comments. The background: Northren Lights from feminized seed germinated in rockwool. Growing medium is coco coir Nutrients are Canna AB Lights are (2) CFL 42 wattt in dome reflector tap and nutes ph'd to 5.9/6.0 temp range in interior grow box 68-72F Plant started off great, short,bushy and robust. At some point I noticed the brown tips that on some leaves progressed to center of leaf. At first I thought Heat/Light stress, but I think I've ruled that out because the tops of colas are not affected, only mid and lower leaves. Second, nute burn. Could only 25%-33% of Canna AB max dose cause this much damage. Third, from browsing several problem sympthom sites the only thing I can say remotely looks like it would be a potassaim def. The only thing else I need to disclose it that I've been using white vinegar as ph down. I couldn't get my ph dialed in using ph down, it was either not going down or way too low.
yea, after some further investigation I was leaning towards that too. Question: Doesn't Canna AB already include a cal/mag supplement, or because the plant is in a defciancy to I need to over compensate? What about a feeding of epsom salts?
I believe Cannazyme is where the cal/mag is in the lineup. Are you using the full line or skipping Cannazyme?
Could be lockout from ph also..never used vinegar for ph so not sure how that affects soil ph but how much ph up and down work depends on how many ppms are in the water so ro water only needs a drop or so per gallon and 800ppm needs 5ml or whatever
For the age of your plant I suggest 7.5ml of A&B per gallon of water. I am not sure on the vinegar pH down, but whatever. Collect at least 20% of what you add, up to 50%, as runoff with each feeding. This will provide an adequate amount of nutrition with each feeding as well as remove excess buildup. I also had potassium and magnesium deficiency with Canna. It was particularly bad during early flowering when the EC had been too high and buildup occurred. In this case it's weird because the plant is underfed, but its also under illuminated. So the top of the plant can prioritize nutrients for itself, the bottom of the plant is too far from the lights to need much nutrition, and the middle leafs get shafted as result. Burned leaf usually means burned roots under the soil where you cannot see, which the Cannazym is made for. My suggestion is to get on their feed schedule and use a Fulvic acid for your pH down. Get healthy runoff every time. LST the plant and remove the dead fan leafs. This will allow for a more even canopy and better exposure of the plant for a greater yield. With more balanced lighting and a proper feed program they should rebound fine. If they do need some extra magnesium then start with 1/8tsp Epsom salt per gallon of solution. 1/4tsp if things get real bad. If they need potassium is a little hard to come by with this system in Veg, full strength Cannazym is their answer.
ok thanks for the input. I'm currently feeding at 5ml but was hesitant to go to 7ml because I wanted to rule out nute burn. I've gone back to using GH ph down and have LST the main cola to be somewhat level with the others. I also lowered my lights again as heat stress has been ruled out. I'm goona look into the Cannazym, and will consider the epsom salts in the near future if condition does not change. Also, I was planning on swtiching over to 12/12 this week, should I hold off or can I address the issues during early flowering? The plant 7.5 weeks old. Once again thank-you guys for the time and info!
[quote name='"eezduzit"']ok thanks for the input. I'm currently feeding at 5ml but was hesitant to go to 7ml because I wanted to rule out nute burn. I've gone back to using GH ph down and have LST the main cola to be somewhat level with the others. I also lowered my lights again as heat stress has been ruled out. I'm goona look into the Cannazym, and will consider the epsom salts in the near future if condition does not change. Also, I was planning on swtiching over to 12/12 this week, should I hold off or can I address the issues during early flowering? The plant 7.5 weeks old. Once again thank-you guys for the time and info![/quote] I'd address the issue first, allowing the flowering stage to start off strong
aight, I'll give it some time. Just gave a feeding, w/ 5ml of Canna AB at approx 5.9ph. Tested runoff, it was around 6.5. Overall the plant looks very healthy and strong, I think I'm actually gonna need heavier fishing weights cause she's pulling them off the coco and their just hanging there providing some horizontal bending.