Hello everyone! I am new to this site. I was referred here by ChemGeek. I am a APSP Certified Service Professional operating out of Bethesda MD. I have found these forums very helpful, especially with water chemistry. I have been to Tech 2 pool school and taken numerous advanced water chemistry classes. Alot of the stuff I've learned here wasnt even mentioned in these classes (such as maintaining Free Chlorine 10% of CYA). I've also completed Jandy, Raypak, and Pentair technical schools and am always looking to advanced my swimming pool knowledge. This is a great site!