To be honest, it sounds like spider mites. They are more than likely the little red bugs you are finding.

When the leaves start to die at the tips, it is usually a sign of "nutrient burn". Many will suggest that it is a "nitrogen" problem but I would start small and try to flush your plants or get rid of the miracle grow and transplant. I've had great sucess in the past with miracle grow but the success without it is even better. And one other thing, dont sparay the plants with water unless you live in a very hot climate. They need to breath and if the leaves are drowning, then the plant is sufficating. These are simple problems that most begginers have, so dont sweat it.

What type of Miracle Grow soil are you using?