Dried tips on plants
 

I have two plants out of 30 which have dried browning
tips on the ends of just a few leaves. Both are Vuyls.
They are SH in Prime Agra. Watered weekly weakly
alternating 3-12-6 & 7-9-5. They are in a southeast
window and the sun IS getting stronger these days ...
Any suggestions? More shading? They are otherwise
in good shape and are growing leaves like mad.

I had them all set up according to light needs but they
became shifted around when I was cleaning. Is there
a good at a glance site for light requirements?

TIA

Ruth CM