Tricky plants! hope you guys can help!

[Oxomoco]

Hey new here and new to growing, but seems to be going fairly alright, but recently i transplanted my two oldest plants (sorry not sure how old... i lost track...) into bigger pots, with a new soil mix adding some perlite and clay pebbles, figuring it can't do any harm!

So after i transplanted i flushed the pots with some pH adjusted water, at least as close as i could get to the right pH but ran out of my pH testing kit so was unable to check the final pH.

ANYWAY in the final flush i added some Biobizz nutes (the one for veg state) and probably added a bit too much, but they hadnt had any for around 2 weeks due to a previous issue of strange yellow spots on a few of the lower leaves, leading me to believe i had given them too much nutes already, or it was a nitrogen deficiency, however was unable to really tell so just decided to leave off the nutes, and havent seemed to grow much recently, staying around the same height for over a week prior to the transplant.

However that seems much less of an issue compared to what has now cropped up, hope you guys can help and i'll try to give as much information as you need however i'm not too great with the technicalities

Grown in brandless natural soil... probably not the best idea
Indoors
Northern Lights
Ages roughly around a month?
250W Envirolight
Around 2 inches from the light
Try to water around once a week, however, as a beginner probably worry too much about underwatering and overwatering so it varies
Fed once a week (probably too much...)
NPK i think is 8,2,6 if i read the right part
pH or water used was around 6.5 ish
Temp is around 30-34C and humidity varies from around 60% after watering to around 30-40 i think.
New pots are 15l
And seem bugless to me!

Oh and sorry for the rambling! The first picture of the smaller leaf with the yellow edges (i'm suspecting nute burn but a second opinion would be appreciated) is a separate plant from the pictures of the larger leaves with the worrying claw appearance and strange yellow marks. 2 plants, 2 problems

ps. also sorry if the diagnosis is very obvious but i spent days searching for the answer to my first problem but was unable to get a definite diagnosis, so i am hoping posting a thread with pictures will help much better this time round!

[Mr.GoodStuff]

It's too hot and the plant cannot uptake nutrients properly. You need to lower the temperature to around 25C.

Environment is everything. Without the proper temperature, the plant cannot grow right.

[Oxomoco]

Awesome thanks for the reply, heat never seemed to cross my mind, do you have any ideas of how to lower temperature? i have a fan in there at all times, but i dont really have the resources or time & money and that to create an air extraction system, can't seem to think of any other way to lower the temperature

[Oxomoco]

no other opinions...?