Does anyone have any ideas for low suction repair in toilets before I call the plumber. We have two that are getting worse.

Low suction usually means low/slow drain due to drain blockage or vent blockage. Do you ever hear gurgling or bubbling in the toilets or tub drain? If not try rodding both toilets with a toilet auger. How to Unclog a Toilet Fixture-Use the Toilet Auger or Closet Auger (stubborn clogs)