funnybunny if your in MG soil then flushing may well not have the effect of lessening your nute overload. If I've understood what I've read on these type of soils then pre-fertilized soil work on a time release system that is activated through watering. TANKJR here on the forum is one of the few who can consistantly make MG soil work for him. Maybe he'll spot your thread here and help out.
Perhaps its also worth considering a very careful, gentle transplant into a much smaller pot and soil without so much added feeding. Fox Farms seems to be a popular brand over there, and if the soil doesn't already have it added 20% or so of perlite mixed in will help with drainage. A smaller pot will make it easier for you to water correctly and not end up with a soggy stagnant mess of soil and rotten roots.
You'll definately need fresh air coming in there, old air needs to come out and a small fan to circulate air and ruffle her leaves just a little. She'll like her temperature to be in the region of 75 degF and not too much cooler than that when the lights are off.
Sufficient lighting is also important and there's quite alot of options available for you to choose from. There's a whole section on the forum dedicated to lighting and how its done. You need to be aware that a plants lighting needs change when you go from the growing phase to the flowering phase (not only switching the lights off to 12/12). Plants need a bulb that not only is a decent wattage but the correct kelvin rating (this is the colour temperature of the bulb) and you should see this on the packaging. For the grow phase a kelvin number of 6500 is good and for flowering look for a number in the region of 2700k.