Ok.. I am a new pool owner and I am so thankful I stumbled upon this site! I have been battling algae and realized that my CYA is too high-100 is all I got from my strip and also from LP store. I am getting the suggested test kit so I can SLAM my pool..but first I want to drain some water to get the CYA down. If I understand what I have been reading..I don't have to get a sub pump if I can drain from the bottom?