Fountain nozzles are beautiful and practical additions to a pond should you be able to accommodate one.
If you own an external pond, it is always a good idea to use a fountain nozzle. When in operation, they help circulate the water while improving aeration via surface agitation. Your water temperature would also be lowered.
Surface agitation would also prevent pests like mosquitos from laying eggs.
Having pointed out the benefits, it is also important to factor in that fountains may block your view of the fishes, or hinder feeding. Initially, they may also proof to be attractive to pets like dogs. You might have to bathe that pup at least once!
Please purchase the nozzles for their respective pumps.
FT-01 below 500 L/H
FT-02 500 - 1000 L/H
FT-03 1000 - 2000 L/H
FT-04 2000 - 5000 L/H
FT-05 4000 - 6000 L/H