Leaf edges curling under but healthy

Hey sup guys, can somebody take a look here, i have many edges curling downside why?? Maybe its wrong ph? im saying this because i dont have ph meter atm, im adjusting my waters ph using some chemical shit which shows me the right color (for example green color is ph 7 etc).

Strain: Blue Cheese (Barneys Farm)
Soil: Biobizz Allmix
Light: 250w HPS - 12/12 - 30 cm distance
Container: 11 litre pot
Watering schedule: every 4-5 days with tap water (i let it sit 1-2 days before)
Temperature: 28-30 celcius on the top of plant when lights are on, dark 24-27
pH: my tap water comes out at >8, i adjust it to 6.5 - 7~ (i cant be exactly, no electronic ph meter atm)
Nutes: Biobizz grow,bloom,topmax,heaven (ppm < 900). I also used molasses once, i'm planning to use again after 3 weeks
Plant training: none

N abundance...............dark green clawed leaves. easy on the water and feeds

30C is hot...................

Yes i know, 30 C is hot but nothing much i can do. I'm trying to keep it as low as i can using freeze bottled water. It drops around to 27~
My biobizz grow formula is 4-3-6 , and bloom 2-6-3.5, dosages are 2 ml grow per litre, 1.5 ml bloom per litre.

Plant's age: 36 day (switched to 12/12 5 days before)
Plant's height: 27 cm

make sure you're not over-watering also. water when pot feels light. skip a feed. let dry out, and re-assess

Thank you, i will inform next week because i watered and feed after i made this thread.

Bio bizz only recommend 1ml per l of grow formula when in flower, have you got top max aswell? bio bizz do a chart for feeding doses right through from veg to flower as dosages vary from week to week. if i can find it ill put thier recommendations up on here for you.

Bio Bizz feed schedule for flower is week 1,1ml per l grow, 1ml per l bloom, 1ml per l top max.
weeks 2+3 1ml per l grow, 2 ml per l bloom, 1ml per l top max.
weeks 4+5 1ml per l grow, 3 ml per l bloom, 1ml per l top max.
weeks 6,7+8 1 ml per l grow, 4ml per l bloom, 4 ml per l top max.
This is of chart for plants in all mix, hope this helps.

Water and Fertilizer , it will make a crop and it will also break a crop ! The pictures speak for themselves and most likely others note this as well .

Hey again after 8 days, last time i watered without any fert and they seem to be healthier now, you can take a look. A bit droopy but edges are now straight, and leaf color getting softier.

Does someone know what drooping of the lower leaves means? They seems to have kinda lost support and fell down. My water schedule is good, i'm not over-watering or under.