In a 250L aquarium, i have the filter provided by the tank manufacturer. However, the tank is the part i wanted, the rest beeing a bit low quality. I made a new box for the lights because the suplied one was deficient, and now i am making my own filter. Indeed, this tank (Aquadream104) had an internal filter (Biobox 2), but i am really unsatisfied with it.
First of all, it is a big black box, wich is ugly in this tank. The fishes often find their way in it, by jumping, and stay stuck in there.
But the most important is that it gets clogged very often, an thus stop filtering anything. I am now working on an external replacement filter for this.
I want it to be external so that it can easyly be serviced, and to have less ugly stuff in the tank.
This tank is for my grand mother, and it thus must be low maintenance, and very simple to clean.
I now have a functionnal prototype that really cleaned the water.
water tight food grade plastic box, with lid
silicon tubing (food safe)
plastic L shaped bars
aquarium silicon (must be food safe)
connector for the input and output tubing
4 years later, this filter is still running. It worked well, and still does (and will for a little while).
It is an easy filter to make, but not the simplest to maintain. Not that it's complex to maintain (you just pull it out of the water, get the sponges and rince those before putting it back in the filter), but it's not quick nor a pleasant experience. Not that i expect it to be super fun to clean a filter, but it's anoying enough to do that i don't do it often enough.
So what would i change?
make sure to have no sharp or pointy plastic bits to avoid hurting yourself when cleaning the filter
have the pump separated from the filter media (but why not, surrounded by sponges to absorb vibrations)
have the filter output pipe not going trough all the filtration media (as of now, it sometimes pops out when you pull the sponges)
if possible, have separated compartments for each media (at least for bio media);
if possible, have each compartment accessible without removing everything.
As for this project, it is very unlikely to see some updates, since i'm working on two separated projects that will simply replace this one :
a 3D printable internal aquarium filter, adressing most of the updates i wanted. This one will be entirely 3D printed (appart from the pump and the media of course), so making one simply consists of printing stuff, assembling the parts, installing the pump and the media, and use it;
an external filter using a bucket, way more "hacky", but it will provide an enormous filtering media capacity, and i will have to clean it very rarely.
I'll add links for those projects here when i make the projects pages.
It's been at least a month since i installed this filter. It really performs well, the water is really much cleaner than previously. It is really easily cleaned, and i don't have to stop it in order to do so.
However, it has to be cleaned to often for my taste. I think that i need a larger filter box, with larger filtering masses. I also want to include specific media for biological filtration (as of now, bacteria are simply in the sponges, with bio balls i expect to have a larger and more stable nitrite consuming bacteria population).
I will have access to a laser cutter, so i will probably make a plexiglass box (or any other plastic, i don't need it to be transparant, only non-toxic). Once i design the filter box, i will release the files to reproduce it.
I am also working on a smaller 3d printable version for my smaller tanks (54L and 30L). It may be multi-part, with assembling if needed, however i want the inlet and outlet to be included in the box rather than having to buy and glue tubing connectors.
The original filter was completely submersed. For this filter, i want to only have the pump submersed, with a prefilter to avoid sucking small fishes and shrimplets into the filter. The filtering masses will be in a box over the water surface, in order to have it easily servicable. The plan is to have a rectangular box, with one water input, and one water output, and multiple compartments. The closer from the input, the larger are the holes in the filtering mass. I thus will place large holes sponge near the entrance, smaller holes sponge afterwards, then perlon in the third compartement. I will leave the last compartment for biological filtration mass.
However, i may later use a specific design for biological filtration, with cascading water flow, as it maximizes the oxygen entry into the water and thus bacteria developpement (it is call semi-submerged filter). For now, i want to have a good mechanical filtration, and have it easily servicable.