Had a energy audit by the electric company. They advised to change to a variable speed pump to save energy. I have two 1 hp pumps one is labeled "clean" and the other is labeled "filter" I run one in the daytime as it runs my solar pool heater. I run the other at night for my in pool cleaning. My pool is a 10,000 gallon play pool. Pool and equipment are approximately 16 years old. When I asked the audit fellow if I had to change both pumps he said no just have it plumbed so one pump can run both clean and filter. Is that correct or do I need to change both pumps to variable speed? It seems to me that the costs would defeat the savings. Any advise would be appreciated. Thanks