Filter Foam

[Aqua sobriquet]

Many external filters seem to come with two or even three different grades of foam, coarse, medium and fine. Is there really that much point in this? The coarse stuff doesn’t seem to collect anything from my Aquariums when I’ve used it although I suppose it’s working on a biological level to some degree. I’m just wondering if I’d be better off just using medium foam the next time I set up a new filter or do a change. If anyone has any insights on this please mention porosity if you can for clarity. I do use other biological media like Siporax in my filters so I’m mainly using foam as a mechanical first stage as it were.

 

[Zeus.]

Coarse and Medium foam is all I used in my 500L. Fine clogs up to quickly and then you get a big reduction in filter output and tank turnover. Less so critical in low tech setups, but even low tech setups benefit from good flow IMO.