I have 6 rooms in multiple locations and for a long time I could not figure out why my plants in just one room would not grow or yield what I expected. Forgot to mention this happens to be my biggest room 12 x 14. Six 1000 watt lights . I started the room about 4 weeks ago plants were looking great then they looked exactly like a Phosphorus (P) deficiency. So I started to check my nutes, ppm, ph, fresh air intake, temp, hunidity, also have a dual burner gen 1 co2, and could not figure out the problem. So I started to remove the yellowing leaves from the plants and was on the computer and noticed these small little insects on the leaves that I had trimed of the plants. I lookeed and deteremined that they are spider mites. So my million dollar question is does spider mite infestation and their work make your plants look like you have a deficiency.