RonDutt

Curious, how does one go about changing the filter? Mine (EX45) is showing as almost time to change (the white strip is almost completely black). Replacing the filter outright would remove quite a bit of bacteria from the ecosystem, but theres no room in the filter to stick in two filters. Do I just leave the old filter in the tank (floating) or...?

elvis

Hey there friend, and welcome
there's an interesting situation .. I'd go the floating option for a few weeks

My 2 cents

DarkFin

Does your filter snap open to where you can insert the other filter, most tetra filters do, floating won't do mush, i would try to get it close to the gravel to where they can multiply on the gravel GOOD LUCK!!!

pepetj

I don't pay attention to replacing filter cartridge because I choose to modify them.

I have smaller, older but similar in chamber design (exception in the placement of the impeller) Tetra models. If you still want to follow manufacturer's instructions, I suggest you tear at least a good portion of the fiber (that should have some slime built on its surface) and place it as close as possible to the replacement cartridge. Keep an eye on your water parameters.

From day one I dismantled the original cartridge and use its snap-on frame to build my DIY version.

I see no point in replacing filter media used for mechanical and biological filtration when gently rinsing it in water from the tank keeps it working optimally.

The problem with the Tetra (and others) design cartridge is that activated charcoal is usually present inside the fiber bag and leaving it after 3 or 4 weeks would more likely than not end up with the charcoal releasing back into the tank undesirable waste.

Pepetj
Santo Domingo

Betafish305ca

i have a whisper filter, and i change it whenever it gets really green and gross, and even cleaning it out doesnt help

Steve420

I'd just rinse it out really well in used tank water and ignore the fact that its telling you to "change" it.

A little irony for ya...

I was just joking with my wife about how we've had our 55g set-up for approx 2 years and I have NEVER replaced a filter cartridge. (okay...I did change 1, but I used the old one to cycle 2 other tanks, so technically its still being used).
But I have a Penguin Bio-Wheel which holds 4 seperate cartridges. other than the slits I made at the bottom to remove the carbon, mine look as good as they did when they were new.