Q.inside tomatos
My plants that I have inside are grape tomatoes. They have fruit on them. I use grow lights on them. They were doing really well then began to turn white-ish. Them seem to also be spindly. Would appreciate advice. Thank you.
If the leaves look like they have a white powder on them, that is powdery mildew, a fungal disease. Please see these articles about it:
http://livegpath.cals.cornell.edu/gallery/tomato/powdery-mildew-on-tomatoes/
https://www.gardeningknowhow.com/plant-problems/disease/powdery-mildew-homemade-and-organic-remedies.htm
Another possibility is tiny white pests on your plants. Some insect pests can appear white, such as whiteflies, thrips, and scale insects. If you have these, you'll be able to see them if you look closely.
Spindly plants are usually not getting the optimal amount of light. If your plants are producing enough fruit, though, it's probably fine to keep the light level where it is, and the spindliness is just an aesthetic problem. If you want them less spindly, you may need to place them near a window too, or you may need to add more grow lights or a mylar reflector. Adding too much nitrogen fertilizer can also cause plants to grow taller too quickly and become spindly.