Cartridge Based Filter?

I have an EasyCrystal Filter, and I've heard that you're supposed to change the cartridge every 4 weeks. It's been over four weeks but I've been reluctant to change the cartridge as I'm afraid that getting rid of the useful bacteria in my old cartridge will destroy my tank's cycle.

Is replacing a filter's cartridge really necessary, and what are the consequences of not replacing it?

 

Don't replace the filter cartridge until the fiber mesh front begins to unravel. Clean your cartridge once a month by submerging it in a bucket of old tank water and rake the gunk off the fiber mesh with the palm of your hand.
If the filter media basket is large enough, place a fluval replacement foam sponge in it. The sponge will work better than a cartridge and last for years.

 

don't wait for it to fall apart, especially if it has carbon inside. the carbon needs to be removed after about 6 weeks. you can cut it open and dump out the carbon. or you can cut off the fiber outside and use it to seed new media. either sponge like A201 suggested or some polyfill and ceramic media.

here's the guide:
https://www.fishlore.com/aquariumfi...tream-aquaclear-and-other-hob-filters.385506/

 

Any idea how to know for sure whether there's carbon in the filter, and where would I be be able to buy the fluval foam sponge without getting a fluval filter?

I've got 4 guppies in my tank right now with maybe half a dozen fry - if something goes wrong while I'm trying to DIY, what would the contingency plan be?

 

Just squeeze the filter cartridge. If you feel small rock-like pebbles, its activated carbon. You can buy Fluval replacement sponges at Petsmart. There are several sizes to choose from.

 

any retail pet store or online pet stores will have them.

cut the fiber material off the old cartridge and place it with the sponge or other new media.

 

You can cut the cartridge open remove the carbon and wrap some poly fill around the frame of the cartridge and also if you have room you can get some ceramic media and put it in a mesh bag or clean nylons and put it at the bottom of your filter or behind your cartridge to help BB grow on it

 

Just remember millions of people change their cartridge filters every day and their tank just chugs along.

 

Slightly late reply, but what will happen if you leave a cartridge (w/ carbon) inside the filter for too long? Things have seemed OK thus far so I've been reluctant to make any changes, but I was thinking of cutting up the cartridge, getting rid of the carbon and putting a new sponge inside on Wednesday when I do a water change.

 

the carbon can only absorb X amount of stuff. once its full its done. if left in the filter too long it can leach some of the stuff back into the tank.