Any power supply that provides 24 Volts DC & 2.5 amps will do the trick. That's a 60 watt supply for a 40 watt rated pump, a little extra head room. Any supply of that rating or larger is fine. Also need to ensure the DC plug that goes into the controller is the proper size & polarity. All the specs are on the bottom of the EcoTech branded power supply.
https://www.amazon.com/dp/B01M65KYVH?psc=1
http://www.ebay.com/itm/NEW-24V-DC-2...-/121977796987
http://www.legrand.ca/onq/structured...nt/pw1060.aspx