I am trying to drain some of my pool to lower my CYA. I have a Sta-Rite System 3 two cartridge filter and it has a drain plug on one side. I usually just stick the vacuum hose inside of this plug to divert the water away from my house when I'm cleaning the cartridges. (the hose doesn't fit perfectly, so some water spills out the sides) Now, I'm trying to remove about 5,000 gallons from the pool and was wondering if there was some type of hose I could put into this drain plug that fits exactly? I saw some flat backwash hoses, but i'm not sure how I would attach these since I just have an open hole at the drain plug. Thanks.