By David Midgley - I currently have 14 tanks in my fish garage – all setup with varying species of Lamprologines. I keep Julidochromis, Chalinochromis and the odd Neolamprologus. Some readers will know I am also involved with ACE (Australian Cichlid Enthusiasts – an online association of cichlid keepers (current numbering well over 1000 members). We get a large number of queries about which types of filters are best for African cichlid aquariums. I run virtually all my tanks on simple air driven filters, and while I know the hobby is obsessed with water turnover, powerheads and other “hardware” I thought it was worth a brief look at another method of filtration – once more popular now out of style.
In most of my tanks (most are 80 litre, 2’ tanks) I have a single corner filter. I don't have undergravel filters in any of the tanks – nor do I use additional filtration in these tanks such as canister or HOB filters. I don’t have any unexplained fish deaths, in my sporadic checks for ammonia and nitrite and am yet to find
I have been setting up my corner filters in much the same way for some time. I half fill them with a coarse filter material. This is usually gravel, very coarse shell grit or the ceramic noodles often available for filling canister filters. Below this, ie: closer to the bottom of the filter, I put a layer (3-5cm) of filter wool. The order of these materials is probably unimportant, though if you set the filter up the other way around you need to change your filter wool more frequently. In a world that sells “bioballs” this filter doesn’t seem to have enough biological filtration. But it works – and as such, must have. Moreover, all my tanks are high pH (8.0ish), any ammonia in these tanks is far more toxic than at lower pH’s so I’ve a lot of confidence in the system.
So if they are so good – why doesn’t everyone use them? I think this is a matter of aesthetics – these aren't the most beautiful of filters – they sit in the corner (or in my case, the middle of my tank, I’m proud of my erroneously named “corner” filters) and do their work. Additionally, in larger aquariums, single corner filters aren't sufficient, to get them to work you need more than one. While I do like the humble corner filter I don’t like the idea of having six in a larger aquarium, I’m keeping fish, not filters, after all. In such tanks, sumps (or above tank trickle filters) or a variety of other filters are superior.
If you have a small tank or a few small tanks and you want an efficient, inexpensive (mine cost me ~$3.95 ea!!) filter then these are the filters for you!