I would flush for a week with pure water. Check your ph level before watering. depending on your medium, ph levels are more tolerable. soil medium ph levels are more forgiving and with 7ish you should be fine. i use a soilless media that recommends ph levels of 5.5-6.5, and most hydro applications should be 5.2-5.8.
If the ph levels were too high it could cause spots as well as high heat. as for the leaves getting better they won't. once they are damaged they are damaged for good. but don't pull them off as they are still powerhouses for the plant.
most 150w hps that i have seen have the ballast attached to the hood, if this is the case,when you get that hps, ventilation is key, but don't get ventilation confused with cooling. there is still going to be radiant heat from the hood and ballast shield that will cause your tent to stay hot. if you don't actually have COOL air coming in your temps will remain high.
if you can find a 150w remote ballast that will help you tremendously with heat inside your tent as the ballast can be placed usually up to 10 ft away. but you will still most likely need a cool air source to keep temps down.
this is what i found from using larger hid's. but hid's none the less all get hot soooo.... get some pics up! like to see how good they are looking!!