howdy there,whats going on with my lil glue gelato...

It's hard to say! Did the soil smell like cat piss? I am sure cat urine could stunt a plant, but It would likely give off its distinctive aroma. I wouldn't be worried about spiders like the ones I saw earlier in your journal, they shouldn't harm your plants. Spider mites could, but I don't see any signs on your leaves of mite feeding. It could be an environmental issue, as 35c is very hot and that particular plant may have been more susceptible to heat stress than the rest. Plants in pots are at a greater risk of their roots over heating as well. That would be my guess, assuming none of the other plants are having nutrient issues under the same feeding/watering regime. The soil isn't getting too dry, is it? That can also affect the leaf tips. Hopefully the plant recovers!