Any ideas?

Plant is in Supersoil, 3 gal smartpot, vegged for about 6 weeks and flipped to 12/12 4 or 5 days ago. Seems to be only plant in the room giving me trouble. Gave it a feed of Iguana Juice couple days ago at half strength as it was yellowing just a bit, and this happened over last couple days. I use RO water, but have lime and epsom salts added to soil... Could this be a CAL/MAG issue? Was a lower leaf similar spot to yellowing one in third pic. Strain is Grandoggy Purps from Connoseur Seeds.

Thanks in advance!

Thank you for the chart. Looks sort of like a combo of a couple of those... not really sure? The Potassium looks closest, but no spotting... I do have a dwarf banana in the same room that just won't get its act together and now that I think of it, there is a considerable amount of spotting on those leaves, and it keeps losing them as fast as it grows new ones. Not exactly sure if it's in the same soil, but good chance it could be. I'll post pics tonight.

Thanks so far Brewing Up!

I bet its NOT a deficiency caused by underfeeding.

I would guess its overfeeding.

I agree, flush it well at 1/4 strength. The dead parts of the leaves could eventually invite mold and fungus, I would get some sea kelp or liquid karma to give them.

This is a dwarf banana planted about a month before the rest of the plants. It is in fact in the same soil and having the same problems it seems. More spotting on these leaves but similar damage. This plant has been fed nothing but RO water, so if overfeeding is still the supposed problem then I think the soil is just a bit too strong. It was planted with only the bottom 1/3 @ full strength, and the rest of the pot @ 50/50 strength. My other plant in question is probably about bottom 1/2 @ full strength and the rest 50/50.

If overstrength soil is the issue, how do I flush? I imagine the soil is meant to hold nutrients for just a bit longer than if feeding with dead soil and nutes, so is a larger flush necessary? Plain water until runoff for the next week or so?

pH in the soil might be wacked out esp if you're using a really strong soil mix. sometimes it can be down to 6 or as high as 7.5 for the same two mixes, depends on what part of the world shit comes from. looks for all the world like a burn and not a deficiency though, leaves aren't really droopy.

if you're gonna flush then go for about 3x the pot's worth, so therefore 9gal (3 x 3gal yo') but check your pH first.

hope this helps!

k, ty. Soil was mixed up last Spring, so perhaps things got a bit wonky after sitting for so long. Had to take a break from growing for about 6 months so the amount I normally mix up left me with enough in the tub I didn't wanna just chuck it out. I'll check the PH and the PPM of the runoff from these 2 plants as well as a bit of the full strength soil as well. What's the ideal PH range for soil?

K, PH was 5.5 and PPM of the runoff was pretty crazy, so yes, it must be a good bit too strong. Gave it a flush with about 5 gallons tonight, will hit it again tomorrow when the RO tank fills back up. Thanks for the help so far, hope I can bring her back around.