Winter filter pipes

[magpiemale]

Any pointers to stopping filter pipes freezing up ?
Or is it better just to drain them off to protect them from -5 Temps
Magpiemale

[The Moo]

Kept our filter running throughout without problem and I believe we hit -7.5c. I guess the polystyrene based pipe lagging might help though.

[SneakyMcC]

We have 2 filters temporarily set up to filter our pond (Goldies). The returns on the KK5000V froze causing it to overflow during the night. And the mesh screen on our Oase Screenmatic froze. The return n the Oase was partially blocked with ice too!

The water level dropped about 7" before the in-pond pump stopped (don't know why t stopped). My previous set up had the KK filter in a garage so I didn't even consider these filters freezing! The air stones stopped the entire surface freezing over. We were left with 2 10"-12" wholes in the ice (1.25" thick in places). All has thawed without any apparent damage?

[magpiemale]

I kept my waterfall and filters going bit pipework froze breaking my UV quartz glass the pipe split too on thawing.The waterfall froze my Temps were around -6°C