I hold an Aquasana AQ4100 shower filter. How recurrently do I hold to replace the catridges? just wondering coz on their website they recommend shifting the filter catridge...

just wondering coz on their website they recommend shifting the filter catridge every 6 months. i only shower 3-4 times a week (i hold a bath on the other days). also im the with the sole purpose one that uses it since its in my bathroom. the replacements are really $$$. would it really brand that much of a diff if i only replace them every 9 months or so?
Can I grow a small lemon tree indoors?...
Answers:    Many factor determine filter changes, part of water, usage, filter microns and purpose of filter. Nine months is fine for decent hose down, generally you will know by the drop within pressure and soft or hardness of the sea.