Sponge filter assistance

[VioletThePurple]

I just got a sponge filter since my other filter stopped working. Even though the main filter is malfunctional, I don't want to remove it right away because I could risk crashing the cycle. So, how long after having the sponge filter in can I take out the broken filter? Another problem. The sponge filter won't sit on the substrate. It just floats above it. How can I get it on the ground?

 

[Archerfish]

It will take a couple of weeks for the new sponge filter be fully effective. Keep your old filter running until the new filter is ready. Does your sponge filter have suction cups or is it designed to sit on the tank's substrate? If designed to sit on the substrate, I bet the problem is air trapped in the sponge. Keeping the sponge underwater, squeeze the air out of the sponge. How large is your tank and what type (brand) of filters (old and new) do you have?