Your overwatering is causing the brown spots and the yellowing. It's getting critical. Do you have a fan on 'em? If not, do so now. Seriously...let the soil dry out between waterings. Stick your finger in, up to the 2nd knuckle. If you pull it out and there's moist potting mix in/on/under your fingernail, it isn't dry enough to water yet.

I'd ditch the tin foil too. It retains more CFL heat, than it reflects usable lumens. By the time the (23w and 30w CFL) light gets to the foil, then reflects back to the plant...the light is too weak to properly promote photosynthesis. For higher-watt CFL bulbs, the heat is still more of an issue, but the added lumens aren't necessarily worth the heat. (keep fan's on 'em)
Flat white paint works best.