Hi all, First time grower here, and I have some concerns regarding the state of some of the leaves on my plant. I've done a bunch of research before coming here, but I'm hoping that some of your more experienced guys would be able to pitch in with your greatly appreciated expertise and knowledge. As you can see in the pictures, there are varying types of potential pathology in different leaves. Here are my grow details; - Med Gom 1.0 Feminised autoflower growing in coco coir. - Using the following nutrient schedule: http://www.growweedeasy.com/sites/growweedeasy.com/files/coco-coir-flora-series-schedule.pdf - The current age of the plant is 6 weeks + 2 days. - I mix 1 gallon of nutes on the first day of each week and keep it for a week maximum. - I pH balance the nutes to between 5.5-6.5, generally closer to 5.5. I broke my pH meter about 3 weeks ago and I am waiting on a replacement to arrive. I've been guestimating the amount of pH Down I add to the mix based on the first few mixes - I found it took 17 drops of pH Down to drop the pH from 7.4 to 5.5. - I water the plant with nutrients the morning of every odd day. Every even day I water with non-pH balanced tap water. - When I water the plant I flood the pot completely so that there's about 2-3cm of water above the soil, let it drain through, and then I remove the run off. - I live in an area with hard water 1. I've noticed that the leaves that yellow and die off are the oldest, lowest leaves. That would be consistent with a nitrogen deficiency, however there's a heap of nitrogen in the General Hydroponics nutes I mix in so I wouldn't have expected that. It's my first plant so I'm not sure, but it struck me as a possibility that leaves will autodie once they reach a certain age. I'm also a bit confused given that; 2. There's tip yellowing on some of the higher leaves, which would be consistent with nutrient burn. 3. There's other darkening/discolouring/patching on other leaves which I've not been able to match to a particular problem when looking this stuff up online. 4. The tallest leaves around the main cola don't look the greatest. I'm thinking there may be a degree of heat stress or light burn. As you can see by the picture of the grow box there's not really much I can do about it at the moment as I'm size restricted. Any comments/advice/criticism would be greatly appreciated.
Well I would guess it's you're ph. A ph of 5.5 is a little low. When you get you're ph meter, ph you're feed/water to 5.8 to 6.0. 6.5 is to high for coco in my experience. You're going to need to do a flush itch some RO water. Use the hydro side of the chart. I grow in coco as well. This is an auto I'm growing. She about 4' in height. Sent from my iPad using Grasscity Forum mobile app
Have you ever rechecked the pH of that nutrient solution after it has set for a week? The pH will start to rise after a few days just sitting there. I learned this lesson several years ago with water. I would draw up a bunch and correct the pH and just store it in a dark closet never thinking that the pH might fluctuate. I started having issues and didn't know why and checked it one day and it was 4 points off. I don't store nutes. I only mix up enough to take care of that day and no more. That very likely could be some of your problem here. Why are you growing in Coco if you're not doing a hydro grow? I would've put that plant into some good formulated grow soil instead of Coco because it offers the plant absolutely nothing other than stability to stand up. Do a soil grow next time. They're much easier since the soil provides the basic nutrients for the plant for the most part and nutrients are just given as supplementation. My guess is pH problems with your water combined with pH of nutes being off. When you're growing inside, pH is a big deal and you need a reliable way to check it. To get a decent pH meter, you're going to have to throw down $75 to $100. I just bought a new BlueLab a few days ago and it ran about $80, but they are the Cadillac of pH testers. Flush it with tap water 3:1, water/gallon size container with the last couple of gallons going through properly pH adjusted.. Put it back under the lights and leave it alone for a few days to distress and dry up some. Then start nutes back at a very diluted dose and bring up ppm's from there. Hope this helps you out some. TWW
light burn and heat stress I think are playing a huge part ,what are your temps inside the grow and at the top of your canopy is it hot with your hand, my 2 cents worth