For what it's worth --- I had a Dolphin Diagnostic which was nothing but trouble , Sold it on Ebay and bought a top of the line Aquabot (T-4) cost double the Dolphin but is worth every penny. Put it in the pool and forget about it. Come back an hour or two later --- Clean pool .

My advise ----- Buy the best once --- not the cheapest 5 or 6 times.