Hello! I was looking into buying a scuba tank and a regulator for my pool it's about 8 1/2 feet.I was wondering if that's safe to just buy the regulator and the tank we have a air compressor at our house. Anyways can I do this safety, what I'm trying to do is have it at the bottom of the pool every time I swim and be able to go to were it is and grab some air and continue to swim. One question is can I grab a breath and hold it in safely. How much will it cost.Is there anything besides a snorkel for this.