This is a GDP in coco & perlite 60/40, using Jack’s 321 and is in a autopot springpot. Under a HLG 260 Rspec. Yesterday I noticed a few brown spots that I take to be a calcium issue. It has also exhibited what looked to me to be magnesium deficiency. To address the Mg deficiency I increased Epsom Salt by 10%. Sometimes in consecutive feeds and other times skipping one.
I have one other GDP that is starting to show Ca deficiency but to a lesser degree.
During a previous grow similar issues arose and I never really solved the issue. This time I am wanting to get in front of it and deal with it now rather than later. Untreated I know it will worsen.
It is tough to get decent overall plant photo because of the frame, but…
I wanted to run this by you before I did something stupid. My first thought is to drain the reservoir and put a couple of gallons of 5.8 pH plain water (mix of tap & RO - 50ppm) back in the reservoir. Give it a day, empty and refill with Jack’s and MKP (just flipped and starting 2-2-2-1.2 MKP mix.
Hmm? Maybe I can’t tell the difference between Mg or K deficiency. However, I wonder if it some sort of pH issue cause lock out.
I drained the res and will put in 10L with CalMag and MKP pH to 6.0 ppm 490
I did not check trays. Good thought. I will next time I have an issue. Didn’t think of it this time. I did check the res. and it was 5.7. It did not have time to drift up because it was just filled the day before. @ash93 I drained the reservoir and replaced with pH 6.0.
Going forward I will increase Epsom salt to 1.4g / gallon and up @Nicky Part A 10%