Oliver Knott: Lily Pipes
Oliver Knott on how to handle filter glassware

In this short video, Oliver Knott, aquascaper of international fame, shares a couple of tips on how to properly handle filter in- and outflows made of glass. In the aquascaping jargon, we call this piece of glassware "Lily Pipe", and we distinguish between the filter inlet (inflow) and the filter outlet (outflow). Different outlet shapes produce different types of currents. The classic form, imitating a lily flower (hence the name "Lily Pipe") creates a moderate current of water in the aquarium. A straight filter outlet creates a stronger and more punctual flow. More information about the different Lily Pipe outlets can be found in the article "Lily Pipes" in our Aquascaping Wiki.

In this video, Oliver Knott also shares valuable hints and tips how to easily pull a filter hose over a glass filter tube, without any risk of breakage. In the short film, he falls back on the easy-to-use method of simply heating the hose in a hot water bath. In our article "hose diameters and glass ware" we have covered this topic in more detail. Common hose diameters are presented, and we explain which size of Lily Pipe goes with them. Moreover, we give further details on the assembly and disassembly of hose and filter inlet and outlet in our Wiki article.

Towards the end of the clip, Oliver Knott demonstrates the installation of inflow and outflow glassware in an aquarium. Depending on the position of the in- and outflows, you can realize different ways of water circulation in your aquarium. The ADA Gallery in Japan has made lifting the Lily Pipe during the night quite popular. This causes a stronger surface movement, which provides a better aeration of the water during the dark hours. This can be quite beneficial since the aquatic plants don't photosynthesize during the night and therefore don't produce oxygen. Aquarium plants consume oxygen at night, which may further aggravate the problem: Lifting the Lily Pipe can help prevent an impending shortage in oxygen.

moving water surface

If you raise the filter outlet temporarily, the so-called residue film on the water surface in the aquarium is eliminated - another advantage. This visible film on the water surface often consists of microorganisms such as bacteria and algae, however, residue fats and proteins might also form part it. The increased surface movement caused by the raised Lily Pipe prevents the film from forming a coherent carpet. Please keep in mind that this method may drive out CO2 from the water, which might in turn increase the pH value. Especially in a planted tank, the carbon fertilization needs to be adapted accordingly during the day to compensate for the nightly minus. Further tips on how to get rid of the residue film at the water surface are available in our specific article on the topic.

Product listing

Oliver Knott used the following products in this video:

  • Aqua Rebell OF4 17 mm, glass filter outflow for external filters, for a 16/22 hose diameter. Ensures a moderate flow. A matching clear hose, 17 mm is used, a transparent filter hose for external filters with a 16/22 hose diameter.
  • Aqua Rebell IF4 17 mm, glass filter inflow for external filters for a 16/22 hose diameter. Here, too, a 17mm diameter clear hose is connected.
  • Aqua Rebell JO1 10 mm, glass filter outflow for external filters for a hose diameter of 9/12mm. Guarantees a strong flow in the tank. Hang-on principle: the glassware is just hung over the edge of the aquarium glass, no suction cups are necessary. In the video, Oliver Knott pulls a transparent 10 mm filter hose over the filter outflow.
  • Aqua Rebell MI1 10 mm, glass filter inflow for external filters for a hose diameter of 9/12mm. Hang-on principle: the glassware is just hung over the edge of a side pane, no suction cups are necessary.
  • Aqua Rebell OF2 13 mm, glass filter inflow for external filters for a hose diameter of 12/16mm. Ensures a moderate stream.