Pot growers recommend 5 litres per minute per gallon but I think this is over kill.
Once you have sizeable roots you can lower your solution leaving a gap. This gap will provide oxygen but no pump means no mixing of your nutrients.
The hardest thing on any device is starting wears parts fast, mechanical wise 24 hour run is much easier on the pump.
been bubbling them at full blast and no issues. would love to know if I can turn them down tho...