Swimming pool plumbing Can i run 2 separate pumps 1 for filter and 1 for heater?

By running a swperate pump dedicated to the heater could cause the heater to shut down because to too much volumn of water is passing thru it. The heaters are designed to function with a certain amount of GPM. Exceeding the manufacturer's specs or even diminishing them to nearly nothing will automatically shut the heater down. There are also other technical reasons for not doing what you imply.