Curling Fan Leaves Hydroponic Drip System

Hey everyone this is my first post here so I hope that I can inform everyone enough with the knowledge that I have to get some good tips

I currently run ecosystem drip system and just recently I have noticed that the leaves on the top set of plants are curling. Ive been checking a couple things out but cant really figure out what the problem is and dont know if what I did will revert things back and the leaves will straighten out. Here is some more information.

I run 2 600W HPS
the system drips for about 12 mins every hour
currently using a 2 part nutrient and also added bud fuel with a combination of 1000 ppms from the 2 part nutrients and around 100-150 more ppms from the bud fuel totalling around 1150 ppms
plants are 2 and a half week into flowering
PH is always around 5.5 - 5.7 in the resvoir and within the slabs
temperature is around 80-81 degrees Farenheit
stain is blueberry haze

I only see this happening on the top set of plants and figured it was due to the heat in the room so i recently set up a duct and fan that went from the lamps straight out to the filter in order to remove some of the heat from the top of the room.

If anyone has any input it would be appreciated
i will attach some pictures so you are able to see the setup and understand what i am looking at. Thank you.