HMA how often do you change your cartridges

[biffster]

how often do you change your cartridges on your HMA
filter i have a dispute with a friend of mine about how
often we should change them i said every 12 months
and he says it should be every 3 months the place were
he gets his cartridges from charge him £30 every three months
but the place were i get mine i only pay £17 for mine i change
my sediment cartridge every six months

 

[discusdan]

Depends how much you use it I guess.
Though every 3 months seems excessive even if you where using it every day.

General rule I've heard is every 6 months but some people say 12 is fine with regular use.

£30 seems expensive for replacement filters as well?

 

[biffster]

thats what i thought i change my sediment filter a few times a year and i am
doing 35 to 40% water changes twice a week and i only change my GAC and CB
every 12 months