What is happening to swim's plant?

[the grower]

hi everyone, swim is a relatively new grower and needs some help

swim has got multiple plants, most of them fine, but one of them has shown a particularly slow growth, and has started showing some more symptoms recently

swim has looked over the internet but has found multiple possible deficiencies and diseases that could be the one infecting his plant, including but not limited to

- potassium deficiency
- phosphorus deficiency
- tmv
- mold
- etc.

details and photos:

first some of the tips and edges became yellow and then brown, later on they also got similar spots in the middle of the leaf (not the edge), swim tried solving this by adding more fertilizer, to no effect

grow: window grow, dorm room, currently in veg on 5th node (will be fimmed soon)
fertilizer: npk 7-5-6
other plants: 2, so far seem unaffected
lights: simple blacklights, 2-4 hours a night, 30cm above plants
and it is currently summer there

I'm sure this should be easy to figure out for some of you who've been doing this for a while, swim would greatly appreciate your help

 

[NuttyProfessor]

looks light nute burn and lack of light

 

[the grower]

I don't think lack of light is a problem, it's near a big window at all times, let alone the blacklight, but nute burn would definitely be possible

correct me if I'm wrong however

any solutions you can suggest? - besides not feeding it anymore

thanks for the speedy reply

 

[Weaselcracker]

I was going to say lack of light also. Needs direct sunlight or a grow light of some sort. Try transplanting into a one gallon opaque (not transparent) pot with drain holes, filled with good potting soil with perlite and no nutes.

 

[the grower]

I was going to say lack of light also. Needs direct sunlight or a grow light of some sort. Try transplanting into a one gallon opaque (not transparent) pot with drain holes, filled with good potting soil with perlite and no nutes.

I was gonna replant it in 2 days (need to get another big pot first, the others are already in 2 gallon pots)
this one already has drainholes, I just took it off the little plate beneath it, the potting soil is quality too, and I'm gonna replant them outside in 2 weeks, I just want them to be ready (giving lst atm)

I guess I'll keep this one inside for a bit longer and I'll put the lights on it a little longer every night

I've layed off the nutes for 2 days since I already expected that could be it when that made it worse, I've flushed the fuck out of it (don't worry, I've provided excellent drainage)

thanks for the replies, if anyone has more tips as to what to do, don't hesitate :3