Solar Heater and pump speed

Just had solar heater installed yesterday for my 14x28 inground pool in El Paso, Texas.  I’m currently running your PL2605 variable speed pump (excellent unit by the way!).  I used to have the three steps set as follows:  Step 1 - 1100rpm for 18 hours, Step 2 - 2600rpm for 4 hours and Step 3 - 3100rpm for 2 hours.  Running it this way around the clock really kept the water clean, chemicals balanced, energy bills manageable etc.  However, with the solar heater installed, I have to run the pump at least 2350 rpms or the solar system sucks in air.  I feel I’m losing all the advantage of the variable speed pump becasue I can’t run it at low speeds anymore and its going to get expensive.  I could run it at the 2350 for about 8-10 hours during the day to keep the water circulating through the heater so the water stays warm and shut down overnight I guess.  Could you offer any other suggestions to take advantage of the variable speed pump but still have the advantage of the pool heater without running it so fast?