and to day I did a full rez change with only fresh filtered water.
A good flush won't do them any harm but it looks to me like you may have a phosphorus (P) deficiency, have you been using any flowering boosters? Have you checked your PH?

Sativas always look like crap during flower too as they suck all the nutrients out of the leaves.

TomStoner Reviewed by TomStoner on . 5 week 2 days flowering death like problems. need help ok so my plants R 5 weeks and 2 days into flowering 1 of em is a sativa and is looking real bad. the other 1 is an indica and is looking much much better than my sativa. my lights R 3 inches away from the buds. and the lights R cfls and they R 23 watts each and there is 8 of them. the indca looks great. I am thinking that they might be also root bound. Rating: 5