I started my first grow on July 20, so the plants are now 38 days old. They are grown from seed and are the strain Lemon Skunk. There are four of them. I am using a 250w MH for veg and then a 250w HPS for flowering in a 2×2 foot space. I’m using Foxfarm Ocean Forest potting soil. The nutrients I am using are Mexican Bat Guano at 10-2-1 and a new line of organic liquid fertilizers that my local store recommended called Nectar for the Gods. The soil nutrient is 2-5-2 with 3% calcium and 1% magnesium and the supplement is 1-5-1 with 1% calcium. I’ve also been using a growth enhancer with some humic acids and kelp meal in it. The water is right around 6.5 – 6.8 pH after adding nutes.
I didn’t give the plants any nutrients for 2 weeks, from 7/20 – 8/3. At this point, on 8/3 I fed them with about 1/2 the dose of bat guano and the soil nutrient. It was a couple days after this that a little yellowing appeared on the tips of the bottom leaves of a plant. The plants were in small 16 oz cups so I had to water again on 8/6 and did so with ~ 1/4 doses of the main nutrient (2-5-2 +Ca & Mg) and the supplement (1-5-1 +Ca). On 8/11 I fed them again w/ some growth enhancer. They were starting to show signs of what I believed to be N deficiency, so on 8/12 I added about 1/2 tsp bat guano to the base of all plants.
At this point, a number of leaves were getting some yellowing and slight necrosis, all on the lowest leaves and mostly on the tips. I realized that I had probably been overdoing it with the ferts and that I may have messed up the pH. So I flushed the 16 oz cups and then transplanted all the plants to 10"x10"x12" pots on 8/16, watered them in, and that is where they are now.
From 8/16 on, the largest plant started to show some serious yellowing on its leaves and not just on the edges but on the inside of the leaves too. With the plants in new, larger pots, they didn’t require as frequent of watering so I decided to just observe for a while and see what happened. The largest plant developed yellowing on its lowest leaves and mostly between veins so after doing research I decided it could be an Mg deficiency.
On 8/26 I watered them heavily with 1/2 dose of bat guano, the 2-5-2 nutrient and some humic acids. Pretty much immediately after this the yellowing leaves on the largest plant got worse. Since then however, things seem not to be getting any worse.
So to recap, I’ve had some yellowing and necrosis happen on the lowest leaves of the plants, first starting on the edges, but are now starting to present in the middle of the leaves. After doing some research I believe that it is either N or Mg deficiency, nutrient burn or pH problems. The leaves are not super crispy but definitely more than they should be. They are also curling down a bit.
So please, if you can help me out! I haven’t been able to figure out the problem(s) and really need the experience of the people on this forum!
Take a look at the pictures. They are of the largest plant. The first one is from around 8/20 and the second one is from 8/27.