Do fountains turn over water like diffusers do ?

I have trout in my pond and would like to keep them as long as possible and am thinking of getting an aerating fountain to run at night to cool the water and add oxygen. My question is will the fountain turn over the water the way a diffuser does as I wan to keep the deeper water cool for the trout .I live in WV and have been looking to add some floating plants like duck weed also. Any one have any advice to keep the water cooler ! Thanks

As I understand them, fountains typically intake water quite close to the surface. If that is correct, they wouldn't mix lower (cold) water in with the (warm) surface water.

Whether or not your bottom water got enough O2 AND stayed cold enough for trout is TBD.

IF your fountain pulled water from near the bottom and had a flow rate similar to the lift rate of a bottom diffuser then, yes, it could turn the pond over in a comparable fashion. BUT, a single diffuser at 10 foot depth should be moving about 1600 gallon per minute...the fountain equivalent to that is ONE BIG PUMP. If your pond would require 2 diffusers...that's TWO BIG PUMPS and so on.

Think Twice about Duck Weed! If it likes your pond, it will cover the surface in no time. If it does not like you pond, it won't survive. It's an all or nothing deal. Most DW covered ponds that I have seen have been old, shallow and muck filled...ie full of nutrients. If you decide you don't like it, it's hard/expensive to get rid of.

I have a similar question. If I use a submersible water pump that can pump 1100 GPH, and pump it so that it creates a waterfall. Does the water coming off the waterfall and disturbing the water add to the amount of GPH of water displacement I can expect? Or is it simply, if I use a 1100 GPH water pump, it's only turning over 1100 GPH of water? I was thinking about making a skimmer that uses this pump to pull debris in and then pump the "clean" water back over a waterfall. Sort of killing 2 birds with one stone

G.Dub, Pumping water to a water fall will NOT increase the flow rate of the pump. And you need to be carful expecting the advertised rated flow of any pump if the actual flow is important to you. Many submersible pumps are centrifugal types and will lose flow the higher up you pump it from the water line. A pump curve from the manufacturer will tell you what to expect compared to head pressure (pumped height above water level).