Rust Spots On Leaves? Leaves Curling Up?

Hi all. Here is some information on my girls.

This is an indoor grow.
Medium is rockwool
The PH is always at 5.8 - 6.0.
The temp is at 72-79 degrees.
Tap water PPM is at 250-300 before I add nutes.
I water once a day.
These plants were clones. The mother was raised in soil.

I vegged for 3 weeks (1000 MH) before moving into flower (1000w HID). The picture is from the last day of week 1 flower.

The edges are curling up. Some people call it taco-ing I guess. I have never encountered this before. What's wrong with it?

Also, I noticed VERY SUDDENLY one day that some of the fan leaves developed rust color spots on it.

Can anyone please help?

Rust color spots are either caused by a calcium deficiency or splashes of fertilizer water. The leaf curl can be caused by multiple things. I'd lower the pH to 5.6-5.7 and you should be watering more often than once a day.......the water temp is too high at 76-79. Your tap water is too high of minerals and should never be above 200 ppm when mixing with fertilizer. You have multiple issues going on- go back to dirt- you'll be better off.