How can I build a bypass filter for denitrification?

Hello,

the construction principle is actually very easy:
all you need is a chamber equipped with intake and an outlet connectors, which is filled with sera siporax Professional [0.5 liters per each 200 liters (17.5 fl.oz. per each 44 US gal.) of water].

For example, you can use a canister filter that you do not need any more otherwise. It is then operated passively, i.e. without the built-in motor. You can even take out the impeller entirely as to improve water flow.

The bypass filter is connected to the biofilter by splitting the biofilter outlet via an adjustable T-piece in a way that about 1% of the outlet water are directed into the nitrate filter - the rest is of course directed back into the aquarium, just like the nitrate filter outlet.

Both filters can also be internal filters, they are then connected in a similar way.

It is important that the nitrate filter, has no direct connection to the air and is operated with a slow water flow as to ensure low oxygen conditions.

Best regards

sera GmbH
Dr. Bodo Schnell