Internal Corner Filter - Any Opinions?

That looks good. The only concern (I think) would be small fish getting behind it - but that would be a concern with any sucker-mounted pump.

Thanks, both. Yes - I learned a lesson in mid-July that fish can somehow get stuck in the most tiny of places as happened with one of the male tetras. Judging by their crazed behaviour when chasing the females, I'm almost certain that's how it occurred, and when I discovered the filter had slipped down the tank glass, I moved it up, most likely finishing off the process.  So filter wool squashed round every possible potential gap, even if only a couple of mm wide, is an "essential" for me now.

I didn't actually realise that corner filters existed but that one caught my eye as a possibility.  The one on APS website looks a bit chunky - the same problem with many of the non-nano filters - and I'm certain the fish would come to a nasty demise if they collided with the spray bar during their mating and sparring rituals.  Eheim Aquacorner does indeed look good but doesn't seem to have a bigger size.  I see that there are more products on the Eheim website, though, including cylinder shaped ones (eg Aquaball, Biopower), so may investigate those this evening although any thoughts on those in the interim would be welcome.

Was it the Eheim Aquaball 130 you had in your 50-litre tank, @Sue? That looks the strongest contender for me although it does say for 60-130-litre tanks. The Biopowers look to be for larger tanks.

Other "contenders" from yesterday evening's research included:
* Tetra IN Internal 600 Plus filter, flow rate 300-600 lph, 28H/8W/6Dcm, but the height is 28cm which is maybe a bit tall for my tank.
* Aqua One Moray 320 Internal Filter, flow rate 320 lph, but with a height of 29cm.
* Interpet Internal Power Filter PF2, flow rate up to 500 lph, with a seemingly suitable height of 25cm, but the 1 review on the website I saw it on (SwellUK, Feefo review) states that it was too big for the customer's 54-litre tank and there are a lot of negative reviews on Amazon. [Note to self: the next size down PF1, for 45-68L/36-80L aquariums may be an option]
* JBL Cristal Profi, i60
* the previously mentioned BioPlus 100 Internal Corner Filter, flow rate 500 lph, 27H/?12W/?11Dm, but with a height of 27cm.

Therefore, it looks as though the Eheim Aquaball is the one I'll opt for.

I forgot to mention 2 things.

The 130 would be fine for your tank. You can turn the flow rate down if you think it is too strong and it would go in a larger tank should you ever upgrade.


I would recommend that anyone buying an Aquaball or Biopower to keep a spare impeller shaft in the cupboard.  They are ceramic and easy to break. I know, I have broken several. They only cost about £5 and it is worth it for peace of mind. The part number is given in the manual (which is on Eheim's website) to make sure you get the right one.

I have just got the one from the 50 litre out of the cupboard.

The diameter of the basket is 68 mm; the part the pump sits in is slightly wider and that is 79 mm.
Mine has the old bracket, so looking in the 180 litre at the biopowers which have the new bracket I would guess the body of the filter sits about 20 mm away from the glass.

As far as height is concerned, the 60 (one basket and top box under the pump) is 150 mm, though the flow adjuster stick up a bit higher than that. The 130 (2 baskets and a top box under the pump) is 210 mm plus the flow regulator.

The current aquaballs are slightly different from mine, they are like my biopowers in construction. With my aquaball the baskets just push together and the cylinder the baskets make has flat sides. The current range has the clip method of joining them together. If you look at a photo of one you can see a flange that sticks out at the top of each section. Since they use the same sponge, the baskets are the same size inside. I have the manual for the older version and the sponge part number is the same, and it is the same for the bottom basket of the biopower.
I think that 96 mm quoted diameter includes the flange. The body of the cylinder is not that big..............


To confirm, I have just lifted a biopower out of the tank and measured it. The main body of the baskets is just under 70 mm. From the outside edge of the flange to the back of the hook that slots in the bracket, it is just under 100mm. If you look on Eheim's website at the pictures of the Aquaballs there is one showing all the parts. You can just make out the hook at the back of the top section. The picture of the assembled filter shows the flange on the baskets quite clearly. The 96 mm includes both the flange and the hook.




I hope that is not too confusing