Garden ponds

Ponds which are neither biotope nor koi ponds

Let’s now mention ponds which are neither pure biotope ponds nor pure koi ponds. You might call them “mixed ponds”. And if you love ponds with marsh plants, but also love goldfish and koi, this might be the right choice for you. Fans of the pure pond types wouldn’t recommend this, but most ponds are “mixed ponds” anyway.

Zoning of the ponds

The design of mixed ponds is a matter of taste of course. But there are a few basic rules you should follow: Flat zones increase the surface and the opportunity for oxygen enrichment without technical intervention. Flat zones are also very suitable for marsh plants which withdraw a lot of nutrients from the water and, as a result, the algae’s nutritional basis. Your pond needs a depth of at least 180 cm for the animals to survive a hard winter. If you use a filter (highly recommended), the intake strainer should NOT be positioned at the deepest point, because it will become soiled faster there and it will mix together all the water layers. The warm water is always at the top and the colder below. In summer especially this is a good thing because the colder water can bind more oxygen. If the intake strainer is directly on top of the pump, a large bucket can be used to raise the pump off the bottom.

The thermocline

At first warm – then suddenly cold

Thermocline, separating 20 °C surface water from 14 ° C cold deep water

When the water warms up at the top a thermocline forms. Below it the water can be 10 ° colder!

It’s raining leaves

Foliage leads to a mudbath

One thing you definitely need to deal with is the vegetation around the pond. Most of our trees and bushes lose their foliage in autumn and large quantities of this end up in the pond. There it sinks to the bottom and forms a layer of sludge. Bacteria decompose the organic matter, consuming enormous amounts of oxygen. This can be so much that the water dwellers may suffer. Preventing leaves from entering the water is the best method, removing them is the second best method.

Lack of oxygen at the bottom leads to purple bacteria, which look nice, but indicate oxygen depletion in combination with putrefaction processes.

Birth control

Overpopulation in the pond

When stocking your fish please remember that they have sex and produce offspring. Your pond might quickly become overpopulated. Ask your specialist pond supplies dealer or your pet shop if they would like your fish offspring.