Oliver Knott: DIY syphon
A DIY guide to building a syphon

In this video tutorial, Oliver Knott shows you how to build a syphon from simple means with which you can extract sludge off the soil in your aquarium. The products are of course offered by other manufacturers as well, but as Oliver says in the clip, emergencies sometimes call for a quick do-it-yourself solution.

For your DIY syphon you’ll only need a common filter hose, which is available in different diameters. Another material needed is a clean PET bottle plus its cap. The butt-end is cut off, as shown in the video below. With a little help of a drill, the cap of the PET bottle is provided with a sufficiently large hole, into which the hose is inserted. The outer diameter of the hose needs to correspond with the diameter of the drill. It won’t do harm if the hole is a bit smaller (a millimeter or so), which makes it a littler harder to insert the hose, but also prevents it from sliding out all too easy again because there’s just not so much give.

The so-called syphoning of the soil is necessary in aquariums with strong fish stock, few decomposers (recyclers of food residues such as shrimp and snails), and in less-planted aquariums. Especially in breeding tanks, feeding causes too much organic ballast, which accumulates in the soil in the form of sludge. This should be extracted in regular intervals to extract the sludge and prevent rot. Since sludge can infiltrate quite deeply, especially into coarser ground such as gravel, it shold be extracted in regular intervals, using a syphon. Otherwise, there may be compactions, associated shortage of oxygen and even rot in the soil, releasing pollutants into the aquarium water.