In regards to biological filtration.....keep in mind that you filter is only going to break down what waste is actually there. You can place a huge wet/dry on a 20L and it will only grow enough ammonia/nitrite reducing bacteria to handle what waste is created by the fish and the food. The good bacteria cannot grow fast enough to handle spikes that are caused by poor maintenance, overfeeding, etc. The only thing this really does is add more water volume to your system.....which can buffer errors. But why not just add this volume to the tank where you can enjoy fish.
On the other side, large filters can do a lot for mechanical filtration. You can have a tank with very little free floating debris.
Colin
On the other side, large filters can do a lot for mechanical filtration. You can have a tank with very little free floating debris.
Colin
