Quit overwatering them, and are you spraying them, too? If so...I'd stop. Is there a fan on 'em?

Ditch the tinfoil. CFL's light doesn't extend far enough to rebound back and be a benefit, but will trap and reflect heat.

No need for additional beneficial bacteria, unless you like barking up the wrong tree. No offense to those that swear by these different types of additives and miracle tonics, but most are unnecessary and some are potentially harmful for either you or your plants.

Learn to grow, then learn to optimize your grow. If you can bring a seedling to harvest without all the unnecessary bells and whistles, you've saved yourself a lifetime of searching for the non-existant "miracle" tonic/tea/mix/incantation/moon phase. (and have saved shitloads of cash in the process :thumbsup