Why would the water back up in the skimmer and look like a water fountain if you shut your filter off for any reason?

This same thing happend to me 3 weeks ago.My problem was the pump basket the gasket was not seating properly,I also noticed lots of air in the pump.I replaced the gasket for about $15.00.That solved my problem.Like you no one could help me eaither.Let me know if this helps.