10.01.2012

Cold water fish or better cool water fish in the living room aquarium

In the course of continuing raising power costs, it might be worse thinking how to lower the operating expenses of an aquarium.

Especially, if you have tanks like me with about 1000 liter content, it causes a considerable amount. The lion's share of the power costs in aquaristics is corsed by the lightening and the heating. The expenses for pumps and filters are therefore ignored.

Illumination

Often an illumination of 0.5 watt per liter will be supposed to realize an optimal plant growing. It is recommended to illuminate the aquarium 12 hours a day to imitate the lenght of days in the tropics. That would means for me to cosume 2190 kWh for the illumination. If you pay 25 Cent/kWh yearly costs of 550 Euro arise. But as i mentioned in the articles Low light nature aquarium and Aquarium Setup Guide it is possible to run beatifull planted tanks with lower or shorter illumination.

Heating

A typical temperature for tropical freshwater tanks is about 26°C, that is on avarage about 5°C difference to room temperature. In order to heat one liter water at 1°C 1,16 Wh are required. If it is considered to need to heat up the water at least 2 times a day to the needed temperature about 4200 kWh per 1000 liter water per year are required that means to pay more than 1000 Euro. This is of course just a rough estimation. If the tanks are not closed the evaporation of the water might cause much more.

For each °C I could save the heating costs decrease for about 200 Euro per year. So why don't look for aquarium fish that can be kept at or near by room temperature?

Cold water fish ?

Typical pond fish like gold fish or local fish species like sunbleak or stickleback are normaly ment if we speak of cold water fish. But these fish are problematic, because they often need much lower temperatures in winter than can easyly be provided without great affort in the living room.

Much more appropriate for the keeping in living rooms are therefore fish that come from subtropical areas of the world. There are a range of interesting tank fish commercial available that can be kept at or near by room temperature.

In the following I would like to put forward some of the fish species that I have kept longer times without problems at room temperature and refere to some examples of other fishs, that might be considered. In my tanks the temperatures range normaly from 20°C at night and 22°C at day. The lost heat of the filters and of course the lightening warm-up the tanks slightly above room temperature. In winter it has to be additionally heated where appropriate (according to stocking and location of the tanks), to suite the needs of the kept species.

Live-bearing tooth carps

A great many of the popular live-bearing tooth carps can be kept without problems at room temperature. In particular, Platy Fish (Xiphophorus maculatus, 18 - 28°C ), Variatus Platy (Xiphophorus variatus, 15 - 28°C), Swortails (Xiphophorus hellerii, 20-28°C) and Guppys (Poecilia reticulata, 20 - 30°C), especially Endler's livebeare (Poecilia wingei, 20 - 28°C) are good examples. Highbred guppies need potential slightly higher temperatures and also the Mexican Molly (Poecilia sphenops, 25 – 28°C) and Yucatan Molly (25 - 28°C) feel not comfortable at room temperatures.

Suitable for an unheated tank in the living room are also some of the Goodeidae from Mexico. I'm keeping and breeding the Butterfly Goodeid (Ameca splendens, 20-30°C) from Mexico for a couple of years at room temperature. In some references a higher minimal temperature is stated but they are also jolly at room temperature.

Asian fish

There are some fish from the subtropical China available that can be ideally kept at room temperature. In one of my tanks the beautifull Reticulated Hillstream Loach (Sewellia lineolata, 18 – 24°C) and the Spotted Hillstream Loach (Gastromyzon punctulatus, 20-26°C) swimming together with White Cloud Mountain Minnows (Tanichthys albonubes, 16 - 24°C).

With relativ low temperatures also the Siamese Algae Eater (Crossocheilus siamensis, 22 – 28°C) and the Siamese Sucking Loach (Gyrinocheilus aymonieri, 22 – 28°C) are confident. Potentially a low heating is needful for this fish. A typical cold water fish is of course the Paradise Fish (Macropodus opercularis, 18 – 30°C).

Fish from Southamerica

There are also beautifull fish from the subropical Southamerica that can be kept by room temperature, as for example the Neon tetra (Paracheirodon innesi, 20 - 28°C) from the headwater of the Amazon river, not to mix up with the Cardinal tetra (Paracheirodon axelrodi, 24 30° C) from the inflows of Rio Negro und des Orinocos, that like it substantially warmer. Furthermore I'm keeping Serpae Tetra(Hyphessobrycon eques, 18 - 29°C).

Many catfish love high temperatures, but the popular Bristle Nose Pleco(Ancistrus spec., 18 - 30°C), the Dwarf Suckermouth Catfish (Othothyropsis piribebuy formerly Otocinclus sp. negros, 18 - 24°C) and the Black Marble Hoplo (Megalechis thoracata, 18 - 28°C) can be kept without heating.

Futhermore some of the armored catfish (Corydoras paleatus, 15 - 29°C; C. aureus, 20-30°C and Scleromystax barbatus, 18-24°C) are satisfied with low temperatures.

Fish from Northamerica

There are some fish from Northamerica, being particularly suitable for unheated tanks, but some of them are only hardly commercial available.

A very special fish is the Rainbow Shiner (Notropis chrosomus, 6 - 26 °C), that indeed can be kept in a garden pond from spring to fall. This is a braizing colored fish, expecially during breeding.

Otherwise the Darters (e.g. Etheostoma caeruleum, 7 - 25 Grad) and Sunfish (Lepomis gibbosus, 7-25°) should be mentioned. Mayby this bass need cooler hibernation. Well suited is also the Flagfish (Jordanella floridae, 18-26° C) from Florida or Mexico.

Fazit

These examples show, that there are a lot of beautifull fish that can be kept at room temperature. Some of this fish are very interesting and attractiv. It'a worth to be concerned with these uncommon fish. Especially the Rainbow Shiner and the Butterfly Goodeids, but also the Hillstream Loach are something special and will certainly get soon an own article.

© Andreas Jäger