Nitrogen deficency with necrosis week 3/4 flowering, pink grapefruit diesel....help!!

Hey riu,

I am having an issue with 2 of my pink grapefruit diesels, which I have identified as a nitrogen deficency, but first let me get you up to speed on the background of these two plants.

I got these plants from a friend who was using a different nutrient line than I do, and upon receiving them, I decided to flush them out with straight ro water. The plants were about 4 weeks old at this point, in a 15 gallon smart pot (only about 10-12 gallons of pro-mix being used). As I said, I flushed them out with about 6 gallons of water each, only to find out later (stupid me!) that the ph was at 4.3! I initially saw the plant yellow on the lower leaves, looked into ro water, and realized I didn't supplement with cal-mag. So I decided to get some botanicare cal-mag, and added 1 tsp per gallon.

Nothing really seemed to change, and then I got a digital ph meter. I checked my ph, realized that the ph was off, and Began feeding again with the correct ph (6.0-6.2), supplementing with ff grow big for nitrogen. I use the full fox farm line as well as botanicare cal mag and dynagro pro-tekt. Im still seeing some yellowing and it is climbing up the plant. So many leaves have already died from necrosis and I'm afraid of how it may have stunted the plants. I usually feed constantly with 2.5-3 gallons per watering, and I haven't flushed them since the first time. I'm on day 30 now in flowering and it is a 56-63 day strain. Help! Experienced growers, what should I do?!

i think your watering too much for a start.

how much is running off from the pots when you give them 3 gallons?

I don't think that is the issue. I water them heavy and wait til they are nice and light ( usually once every 5-6 days). Once again, these are 15 gallon smart pots, so they are extremely hard to overwater. Usually have next to no run off when I water.

pictures...........are you sure its not mag?

I'm trying to figure out how to upload pictures on here still. It seems like it is nitrogen characteristics with the necrosis and the yellowing starting at the tips of the leaves and working its way back. Buds don't appear to be stunted too much (from what I can tell). Plant started yellowing down low initially and is working its way up.

What growing medium are you using? cn

Using straight pro-mix. Full fox farm line, botanicare cal mag, dynagro protect, hydrologic ro system.

Still looking for help! Do I flush to get the ph balanced again, or do I keep running my feeding schedule with a balanced ph?

Still looking for help, watered with 4.5 gal today with half strength mutes and a ph of 6.2. Run off water ph was 7.0.

I think you need to post pics at this point, there's an insert image icon on the top of the quick reply box. Click that to upload from your harddrive.