Phosphorous deficiency?

if leaves are tacoing is normally from RH or temps. not to much P or K in my experience. I aggree the bottom looks like N but if isolated plants shed leaves when they are not getting used.

nitrogen defciency below... but if isolated could just be shedding some leaves. if it progresses, add more N. too much p/k can cause skinny leaves on new growth.. this would normally be accompanied by chlorosis too. it's not about playing mad scientist adding this one week then never again. It's about keeping a healthy and consistent amount of nutrients around the roots. Some nutrients rely on diffusion and some rely more on active transport. The ratio/balance of what exists in the soil is just as important as the overall concentration. You don't necessairly provide based on rate of use for all elements.. sometimes it's more bout the balance of what exists to ensure everythign is available for the plant to grab (active transport) on demand.