Cheese's

As soon as the 2 coteloydon leaves show, photosynthesis begins. Humidity over 60 will suffocate the plant, it will close the stomata on back of leaves to prevent "drowning". Photosynthesis grinds to a halt as does water uptake. 40-55rh Don't focus to much on distance recommendation by manufacturer all they care about is legal liability, get the light close enough to achieve a leaf surface temperature of 86. This is optimal for photosynthesis. Try ambient -83 84 with leds distanced to top of canopy reaches 86.

Actually if tips are burned and straight it is potassium deficiency very first sign. Now if burned and curling up and in. That is nutrition burn.