Why are filters not more user-friendly?

[Maf 2500]

Still not there for me. The Oase prefilter is coarse

No, it is not course. As standard the Biomaster comes with 45ppi prefilter which is the finest foam in the filter. 60 ppi is also available if you want to go finer. (and 30ppi if you want to go the other way.)

And the heater is a bypass path through the rest of the media

Again not true, the heater chamber is the down-pipe in this filter, after pre-filter but before main media.

Having said that, I agree with your general point that canister filters could be designed better.

 

[Djoko Sauza]

Still not there for me. The Oase prefilter is coarse - and that blocks much less often than the fine filter pad, assuming you use one. And the heater is a bypass path through the rest of the media, so it neither filters as efficiently as it could nor heats the water as efficiently as it could. I've only had experience of the smaller FiltroSmart Thermo and I couldn't get enough flow around the heater to get it to work properly, plus the two-cables problem - I imagine the bigger Oase solve the first problem, but not the second.

The path should be:
16mm in (e.g.) -> Primary settlement (optional) -> coarse prefilter -> pump -> medium -> fine pad (EASILY INSPECTABLE/CHANGEABLE!) -> Bio media -> chemical (if required) -> 12mm (e.g.) out.

Impellor pumps used in canisters can tolerate reasonable particulates, so ideally they'd be after the prefilter but before the rest - that way the input (larger diameter) isn't constrained and the output is - so the pump is pushing, not sucking: better, longer-lasting flow and less cavitation therefore smaller pumps and quiter, cheaper filters. Baskets are fine IF they don't bypass (old Hydor Pro filters look good for this). Flow indicator if getting fancy I guess so you can see when to clean - not some fancy electronic gizmo that measure time, just measure the flow (I think Eheim sereis 3 did this?). Inlet and and outlet on the top with the usual easy disconnect, ideally either both pipes and individual pipes (the Tetra I've just received does this, which is good, and seems reasonably OK on bypass too - just prefilter in the wrong place for easy maintenance).

Add in minimising number of seals and gaskets as per Darrell's post and for me we'd be there, but nothing I can find does that so far!

All filters seem to work, all filter the water, all have some means of being cleaned and of shutting off (e.g. external double Eheim taps) - just that no filteris as efficient or as easy to use as they could be. It annoys me that this is a design, not a cost issue. Manufacturers could do better.

Definitely a first-world problem though. I'm not normally this rant-y, I promise 🙂

Definitely agree that the oase is far from perfect. For me it is good enough though.
And you can use finer sponges on the prefilter, up to 60ppi if memory serves me right?

I suppose most folks are satisfied with the quality of filters in the market so therefore there is no pressure on R&D to come up with better products. Even if most improvements would be simple to implement...

 

[orxe87]

Judging by what I’ve seen on the net plenty of folks have made their own external filters. Maybe you could too?

Then I'd just get annoyed at myself for it not being good enough in execution instead of design 🙂
I have thought long and hard about it, but whilst I can visualise a design I'd like, as a consumer I can't see a way of casting plastic of machining s/steel to the level I'd be happy with. I think that is the annoying thing, making it when you have access to the tooling is no harder than making what's out there now, it's just the design.

No, it is not course. As standard the Biomaster comes with 45ppi prefilter which is the finest foam in the filter. 60 ppi is also available if you want to go finer. (and 30ppi if you want to go the other way.)
Again not true, the heater chamber is the down-pipe in this filter, after pre-filter but before main media.

That's interesting, thank you. I didn't know either of those things. Certainly bumps the BioMaster up the list!

Anyway, I've harped on long enough about it, thank you for the help. I'm going to perhaps look at the BioMaster a bit more throughly (add a fine pad?!?). And perhaps look at converting a three-stage DI filter or something, that looks like it might match my requirements though would be ugly as sin.

 

[Aqua sobriquet]

Aesthetics are another issue. I was after a small external to sit next to a Nano and there were a couple that would do the job but so ugly. In some ways, for me at least, the more simple the design the more attractive. Trying to “stylise” some of these products have been a failure in my view: