What are these spots?

[CookieMan]

Hi, any idea what these spots might be on my fan leaves. They are only on 2 out of the 4 plants I have and only on the lowest fan leaves. Plants are just under 1 month old. They are in fox farm ocean forest. Temps were a bit high until recently. They were 85-90, but I just fixed that on Saturday and they are now 77-82.

 

[CookieMan]

Well I tried a foiler feeding with Epsom salts. it seems to have stopped the spread of the brown spots. I will be supplimenting my water with epsom salts now.

 

[JimmyJames905]

That spotting is caused from a PH fluctuation or wrong ph.
Using magnesium sulphate will NOT correct this problem in the long run.
Fox farm Ocean Forest is designed for fertilizer use and has a starting ph of around 6.5. What may have happened is your ph has risen above 7.0 and is now nutrient locked.
This may be caused by not PH adjusting your water to 6.5 before feeding. This depends on what you're feeding it.
It is very unlikely that a 1 month old plant is suffering from Magnesium deficiency using FFOF.

From Fox Farms website
"Garden tip: Perfect for containers and ready to use right out of the bag. Ocean Forest. is pH adjusted at 6.3 to 6.8 to allow for optimum fertilizer uptake. There's no need for nitrogen fertilizers at first; instead try an organic blend like FoxFarm Big Bloom. Liquid Plant Food to encourage strong branching and a sturdy, healthy growth habit."

If you are new to growing and wish to use Fox Farm products I would recommend the Light Warrior as a seed starter soil

and then pot to Ocean Forest for final veg/bloom.

YOU WILL HAVE TO BE VERY ACCURATE WITH YOUR NUTRIENT SCHEDULE IF USING OCEAN FOREST.

Remedy for leaf spotting.
Perform a slurry test for PH.
Adjust soil ph to 6.0-6.5 for seedlings/nurselings
6.5-7.0 for mature plants.

Sent from my iPhone using 420 Magazine Mobile App

 

[CookieMan]

Thanks for the feedback Jimmy. I had seen some luck with the foliar feedings. The growth resumed nicely. I started to see some yellowing on the new growth more recently and I decided that I might be in need of some ferts, being that they are a month old and I'm in 3 gallon pots. I decided to go to the hydro store and pick up some nutes.

The guy at the hydro store was cool and seemed very knowledgeable. Being that prop 64 just passed, I felt at ease to be honest about what i'm growing. He seemed like he knew what he was talking about and wanted all the details on substrate, pot size, and what i'd done so far. He recommended cal mag since i'm using reverse osmosis water. Then he suggested I get the FF Tiger Bloom, and wait a little bit before I start using it. I decided to feed tonight after doing a good examination of the plants. I noticed the new growth is yellowing slightly and some more leaves have slight splotches. I thought it might be just general nutrient shortage. I'm now suspecting that it is possibly due to a high pH. I don't know.

For better or worse, I decided to put one 3 teaspoons in about 3 gallons of water and then water the plants. Then I tested the pH of the nutrient solution. The pH of the water with nutes I used was around 4. I kind of panicked, but decided to test my runoff. The runoff seems to be around 6.5. I will keep a close eye on the plants and monitor their progress.