Dolphin Premier

Filter Bag And Cartridges. Dolphin's multi-layer system takes either a bottom-load filter bag or cartridges, and a fine filter kit comes in the box. The bag suits the weeks when leaves and twigs pile up, and the cartridges make more sense when the water carries dust or pollen. Ultra-fine panels are sold separately. Dolphin does not give a micron figure for any of these filters, so the choice comes down to the kind of debris you see most often.

Weekly Timer And Cycle Length. A default cycle runs for 3 hours, an hour longer than the Dolphin Quantum's, and the built-in weekly timer repeats it every day, every other day or every third day. There is no app, no remote and no delayed start, so you set the schedule by hand rather than from a phone. The timer sits on the power supply, where a button picks the schedule and three lights show which one is set. The schedule lasts one week, though, so you set it again at the start of each week.

Waterline And Suction. The Premier climbs the walls and cleans the waterline, which is where a ring of oil and grime often forms. It uses two combined brushes, which Dolphin does not list as active, so they are not powered on their own. Suction is rated at 4,500 gallons per hour. An anti-tangle swivel keeps the cable from twisting as the robot turns.

Emptying The Filter. This part takes a little more effort. The filter comes out from underneath, so you turn the 20.3-pound robot over to reach it. A full-filter indicator tells you when it is time, so you do not have to guess. It is a red light on the power supply, which blinks when the filter is partly blocked and stays on when it needs emptying. Even so, it is less work than netting leaves out of the pool by hand.

Pool Size And Shape. Dolphin rates the Premier for inground pools up to 50 feet long and names rectangular, round, free-form and kidney shapes. It is not cleared for above-ground pools.