Spots appearing on edges of older leaves and begining of younger

well the title says it. it looks like the begining stages of heat stress. like this only just a few spots on two or three older leaves

and on the younger leaves, of the tops coming out from the bottom nodes, look almost the same, cept the spots are whiter in color and all over the beginning part of the leaves.[2 of em]

I can get pics a little later if its needed.

My temp stays in the 70's and usually around 75F* I am growing in soil [called scotts topsoil] and am in almost a week of flower. no sex yet tho she[or he] will be in a few more days. I'm using just over 200w of CFL and its only one plant. Nice and green.
until i switched to flower i was using 30-10-10[after two weeks] at full strength. ate it right up no nute burn.
soon after next flushing[watering] ill be using the same brand but 20-20-20 or if i can find a higher P-K like 25 ill get that.
And lastly its bagseed.

Another question I have[a first time grower] is i have a oscolating fan on low, half way directed on the plant. What is too much air for it?i mean i assume it would be a bad thing to[while lights on] just leave that fan on low and direct it completely on the plant...leaves all hella twisting almost...lol

Thanks for any help in advanced!

Anyone know?

lol c'mon.

It looks like you may have a Mag deficiency. I know its expensive but if you perfer to grow in soil, you may want to invest in a kit such as this. I will measure all the primary nutrients. Also I recommend foliar feeding for a quick revive of plants that have a nutrient deficiency.