Curling Tips @ 800 ppm TDS?

It seems everything I've read says that curling leaf tips are an indication of too much nutes.

My 4 WW girls are just over a week into flowering. I changed the nute solution to half grow and half bloom totaling 1 Tbs/gal when I started the 12/12 cycle. Also added 2 tsp Liquid Karma/gal. My total TDS was only 800 ppm. I'm using an ebb & flow system with plants flooding every 4 hours of light for 15 min.

I'm using Botanicare CNS17 nutes. Any suggestions? Change nute brand?

how hot is it in there?

Peaks out at about 80 F. 105 cfm exhaust fan and circulating fan aimed thru plants toward light.

800 ppm is pretty low.

Yeah, I thought 800 was on the low end of normal. Read something about a range of 800 to 1200.

I'v been asking a lot about this and what I found from Q&A and my one experience is some plants need and can handle 1200 ppm but some mostly Sativa like lower amounts on nutrients. I am currently growing WOWO and ICE in the same bubble/dwc tank (BAD IDEA). The the ICE can handle 1200 ppm but I'm burning the shit out of the WOWO. I would hang around 800 ppm with your girls and not worry about getting any higher. As for nutrients I love Advanced Nutrients there a bit pricey but they are worth it by far.