Yellow Tips!! help! is it nute burn?

Hey guys.The tips of my plants are yellowing! Help!!

My plants are 18 days into flowering. they are in 360w of LED and temps between 80-85. Humidity 40-60. I just started using Tiger Bloom. So I'm assuming its nute burn. How can I fix!! check it out

if it is it dont look that bad at all.....just do a light flush and tone down the nutes a little next time....should be fine!

How do I go about doing a light flush?

if its dirt just run plain ph'ed water thru the pot twice the amount of pot size.. if hydro then drain and wipe your res and fill and saturate medium with same clean water..