2nd Grow Crispy leaves - Veg - Ebb and Flow

Hi, I would like some advice please.
Im on my second grow, my first one failed.
My set up is as follows.
Ebb and Flow (Flood and drain) Hydroponics.
Plants are in Root riot cubes, in 4inch pots filled with Hydroton(Clay pebbles)
Watering schedule 3x per day for 30 minutes with lights on.
Nutrients Ionic Hydro growth (currently feeding at EC 0.80)
Mars Hydro reflector 48 100W Blurple light 12inches above tops of plant (Both veg and bloom lights activated)
I live in the tropics, so humidty and temp is high. My tent environment has RH 68% Temp is 32°C / 90°F
Im running a fan and carbon extraction fan in the tent. Outdoor humidity around 85%
Plants are tied down for some LST.

Im due to switch to Flowering schedule but wanted to address the problem first.
1 plant is a Amnesia Auto
The other girl is a white widow (non auto)

In the photos, Some of the plant leaves have become a little crispy to touch and are showing signs.of browning edges what is wrong? I cant decide, nutrient burn/phosphorus/light burn or lack of nutrients?

Im keeping the Nutrient schedule lower than recommeneded by Ionic Hydro Grow as last time it seems to be too strong.

Hi
I have tried a number of things.
Reduce the power if the light.
But my tent is still very warm due to my climate. 33C or 91F.
I took off some of the dead or burnt leaves.
Light cycle is 12/12
Feed 3x pwr day with lights on. Each flood for 30mins.
Im on bloom feed now, (Ionic Hydro Bloom) EC 1.8 PH 5.8-6.0

Very concerned about the condition of the leaves.

Any advice ?

Cut back on the nutes,and mist down with ph ed water,I had this issue on my first as well and that helped

Appreciated thank you ! @Jjbc108