Good 1.5" check valves?

[PonDgUrU]

I have check valves between pumps and filters because the water siphons out of my filters back into the pond and it leaves my filter media and hyacinths high and dry.. The current check valves haven't been operating correctly because they get clogged easily and also because debris gets wedged in there and they stick open..
Does anyone have any suggestions for valves that will pass debris into my filters instead of it hanging up?

 

[fishguy306]

Good luck finding one that does a better job. Check valves all suck. You will be better off designing the system so it can't flow back into the pond. Might cause you to lose some flow, though I'm sure a clogged check valve is as well.

 

[PonDgUrU]

Well I found one I think might do the trick I guess I'll find out lol

 

[boldtogether]

Well I found one I think might do the trick I guess I'll find out lol

View attachment 1150635

Beat me to it.
These are the bomb....I only use these.

 

[rodger]

I use brass check valves. The flapper is a weight and they never stick. You would need to go to a big plumbing supply to get them. Also they need to be verticle.