Non Return Valve

[candy429]

Hi all,
some advice needed please. I've just set up my tank and have a external canister filter below the tank. My question is..... Do i need to put non return valves on the hoses in case of a power cut?, might sound a stupid question, but i'm new to tropical fish keeping :blush
thanks for reading

 

[CezzaXV]

Nope, not at all. Non-return valves are normally used on things like air pumps where you don't want water siphoning back up into the electrics. This is irrelevant in the case of external filters as they work by siphoning water into them anyway.