saving money on filter catridges

#2-most people that own tanks if asked "what is the great expence for your setup in the long run" and most will say (filter cartridges).

well an easy way to fix that is when your cartridge is used up (i mean the carbon in it, that's why you have to replace them) just was it off with a power hose to get the junk off. then cut a hole in the top. take out the old carbon and replace with the amount you took out. and it should be replaced every 2-4week. this way you pay $8 every couple months instead of every two weeks.