Browning yellowing leaves

im growing three plants, two have the same things wrong with them. im using two 2' 20 watt flouros and 24-8-16 nutrients. its almost 4 weeks old. the first 3 weeks went good but this last week the leaves turned yellow-brown and started to curl. the growth has slowed alot too in the past week. i think the problem is my nutrients cause i dont know how much to mix with the water. i have a fan on them and my growbox too hot. i havent checked the pH so that may have something to do with it.
please help me out

here are a few pictures

for anyone who has read this... i fixed the problem by flushing it out with pure water and feeding it a very little of nutrients once a week. i dont know if there is a better solution but my plant has completely turned around in the past two weeks

well ya
u should never give them too much nutrient
watch out for root bounds too
good luck

well done on saving the plants, i thought they were gona's by the looks of them

them plants need serious attention or even scrappin

youve done well 2 keep them alive im growin in a nft table