"dodgeyone" wrote in message
...

when i take the pump out of the pond can i put a big air stone in the
filter so i can keep the bacteria in the filter for spring thanks

Your email address suggests you are in the UK which probably means your
system will freeze at least once in winter.

The airstone will help keep it unfrozen for longer but beyond that, the
little bacteria will be at the mercy of the weather.

--
Brian
"Fight like the Devil, die like a gentleman."