Upgrade HOB Filter. What sponge?

I've been wanting to replace cartridges on my HOB filter with sponges instead to save money. Is there a certain type of sponge that works best? I dont know how much pore size matters? I'm not worried about using carbon. I just don't know how well the water can flow through the sponge while still supplying good mechanical filtration. I've never altered anything in my aquarium before.

Related note, will 1in pvc pipe cut up into peices give about the same result as bio rings?

Any brand of HOB filter sponge will be fine. I like Aquaclear HOB filters and sponges and the sponge can be easily cut to whatever size and shape you require. You don't need a sponge with huge holes in it and you don't want a sponge with very small holes (like a kitchen sponge).

When you add new sponges to the filter, you leave the old filter media in the filter for at least 4 weeks so the new filter media can develop the filter bacteria needed to keep the water clean. If you simply throw out the old and replace it with new material, the tank will cycle again and you will have water quality problems.

Pvc pipe and bio rings are not the same. Don't bother about using bio rings either, just use sponges.

Thanks for the great advice again. I just ordered a pack of the brand you suggested.

Any other suggestions for the filter or am i all set with the sponges?

You can add a round sponge (from an internal power filter) to the intake strainer of the filter. There is a video on YouTube that shows someone modifying their HOB.

Just wanted to update.

I got a 3 pack of the sponge you recommended to me. I'm going to leave the cartridge filter in for a while like you said. Eventually I plan on removing it and putting the remaining 2 sponges in its place.

Lmk if this looks like it will work for now and thanks again.