Little introduction first. I have a 18'x34' salt water pool that has been perfect......ti today. I wanted to make a fountain using the port for the vacuum since it's a pressure port. Never used it and it's been plugged for a few years now since I have a electric robot. Anyway when I first unscrewed the plug air bubbles came out along with a nasty Rear smell like rotten eggs. Not really thinking much of it I turned the valve to open the port and a small cloud came out along with the smell. Pool is still crystal clear but now I'm worried now that I research it some afterwards. Seems like itprobably Hydrogen Sulfied in the pipe as it's been closed up for a few years. My question now is there anything I should be worried about with the pool? As a precaution I dumped a gallon of 12% cholorine in the pool. I'm not sure if it's safe to swim in and need to know especially as I have a pool party Im hosting this weekend.