Odd leaf coloration

Hello all! I'm having this yellowing problem with some (not all) of my plants, here's a some background info:

All plants are flowering
My P.H. for soil and water is 6
Im feeding them every other three days 7-10-8
A regular water in between
Highest Temp 80 lowest 68

The problem is this bright yellow starts a the tips in new growth, sometimes the green grows back and other times the leafs die.

any help?

Sounds like you are overwatering them. Try less water and see what happens.

I only water once or twice at the most per week. My plants are happy.

this is awesome with odd coloring or just any problem....

http://www.greenmanspage.com/guides/tables.html

I have had a similar problem and i think it was due to large swings in my ph level