I am thinking about solar heating and no nothing about it. Is it affordable to install after pool is already installed? Is most of it DIY type installation? I could mount it on a east or west facing roof, with complete sunlight all day, so which side would be the best? What is the best brand to check into? Do I require an extra pump to run the solar heating? Any insight would be appreciated because Im tired of a 70 degree pool in May!!!!