ViaAqua 2 Pack X-Large Overflow Filter Box Intake Round Pre-Filter Foam Sponge 5.91" x 4.13" for Aquariums and Ponds (Coarse 25PPI)

I mean real big... So big.. Too big..I Don't use it I have a 40 gallon tank and this took up half my tank I could only get 30 gallons in it when I had this in there

Put one of these on the inlet of your canister filter. Take it out and squeeze it under some water a few times every few weeks. And you can just about run a canister filter indefinitely without cleaning. The amount of debris that gets past this coarse filter is easily broken down in the filter, but the coarse mesh and large size doesn't slow down the flow. Really the only downside is how much space it takes up in the tank. Hide it behind some stem plants and its one of the best tricks of the trade I've learned in my 30+ years of fishkeeping.

I’ve got a pair of these on aquaclear 110 HOB filters on a 65 gallon oranda goldfish aquarium. The goldfish are so messy and these pre filters do a great job of catching bigger debris while giving beneficial bacteria a stronghold.

Lives upto its name ‘xl’. I’d definitely buy it again and if you have fx series or any other heavy hitter, marineland emperor or 375 penguin its highly suggested. Inner diameter is lose for aqua clear 110. Giving it 4 starts because seller has only one size prefilter sponge available.

Holding up well for a couple of years on Fluval 406 and 407 filters. I barely ever have to clean these because the reticulated sponge structure is very coarse. Fantastic as a pre-filter.