I am growing 4 plants, bagseed. Using Fox Farms Ocean Floor soil. Currently not adding nutrients but plan to start this weekend. They are 13 days old. Two days ago one of my plants developed yellow spots, as pictured in the individual photo. It appears to still be growing at an appropriate rate. But the spots are spreading and worsening. Any ideas? Thank you.
first: it's too early for nutes in FFOF -- you can wait ~30 days after initial planting and after each transplant to give nutes. What is the pH of your water going in? What is the pH of your runoff?
Okay thank. I have heard elsewhere 2 weeks into FFOF you can add nutrients, but right now I am going to measure the PH before I introduce anything new to insure the problem is unrelated. It was also mentioned to me that the problem could be a result of low Relative Humidity. Any thoughts on that?
I do not have an accurate measure of the RH level, but I do know where I live, it is a desert, and it is hot. Grow room is about 85F, and is dry, probably RH<25% ish
well you definitely want to get your RH up to 40-60%. Simply sealing the space will do a lot for that.. also 85 is pretty warm - i would call that MAX temp -- try to drop that below 80 (78 is perfect). but with high temps and low humidity you'd normally expect the leaf tips to curl upward... and I don't see any hint of that in these pictures. I'd check your pH first -- pH is going to matter throughout your entire grow. in soil you waant a pH of 6.5 for optimal nutrient absorption. A high pH will lockout iron a low pH will lockout phosphorous, calcium, and magnesium.
I have a PH meter that i will use tonight when its watering time. typically i just stick the probe into the hole in the bottom of the pot, so im getting run off water primarily. Thank you for all your help!
The PH's Read all about 7.2 to 7.0, but i believe it is a little bit of bias in my meter (cuz its a cheap piece of crap). They are probably closer to 7.0-6.8 ish imo.