Should I replace Pentair WhisperFlo Pump with System 3: Mod Media?

Feb 20, 2017
We are having a new liner installed. The company I chose uses Tara Liners. They are going to do a pressure test once the pool is empty. Our pool began to lose water last summer. We are not sure if the liner has a leak or if it's in the pipes. I am praying for a liner leak so we don't have to pull up concrete! My pool company is suggesting that we replace our current pump (Pentair Whisper Flo/Tagelus sand filter) to a System 3 Mod Media Pump/Filter. I wanted to get any feedback on:

1. Tara Liners
2. Sta-Rite System 3: Mod Media Filter (I am clueless, is this a pump and filter or just a filter?)

I appreciate your feedback and suggestions.

Thank you!