Dimensions 200 × 40 × 50 cm

Title Cenote of Dzibilchaltun (Yucatan)

Volume 400L

Background Black vinyl

Lighting 2 x Aquatlantis Easy Led 6800 K (52 W) – time controlled – placement to the right, to mimic shade of the trees and bushes near the cenote bank

Filtration sump 100 liter with different sizes of mechanical filtration media and a biological filtration medium

Plants Nymphaea sp.

Animals Poecilia velifera (12 adults and several offspring) + 6 Thorichthys meeki

Materials white sand, small tufastones, bigger tufastones and tufastone plates to mimic the straight bank of the cenote

Additional Information Extensive biotope description:
This aquarium simulates the Cenote of Dzibilchaltun in the Yucatán peninsula.
Beneath a thin layer of topsoil, the underground of the peninsula is composed of porous limestone plates, deposited in the shallow oceans during past Ice Ages. This type of geological structure is known as the Karst system. As a result, no rivers are found in the Peninsula. Instead of rivers, underground streams and caves are formed. Cenotes are sinkholes (with crystal clear blueish water), that were made by the collapse of limestone rock because of the interaction with groundwater. Some of them have many caves, some of them have a more cylindric form. The water in the cenotes is very hard because of the solution of the limestone (high Ca content – pH 7-8).
The cenote of Dzibilchaltun is an older cenote with practically vertical walls. The only aquatic vegetation consists of large groups of Nymphaea ampla. Sadly enough I still could not find it, neither could I find other Central American Nymphaea. They seem to be dissapeared in the hobby.
Cenotes are the only freshwater source in this area, so they attract lots of animals. In the caves where no light can penetrate the water, one can find the blind Astyanax mexicanus and blind crayfish. Also different kind of livebearers (Poecilia velifera, Gambusia yucatana,…) , cichlids (Thorichthys meeki, Cichlasoma urophthalmus,…) and Rhamdia catfish species live here.
As "wall material" I used tufa-stone. Tufa-stone is a well known limestone that can be used in plates. This will make the water even harder. As fish I used these very nice Poecilia velifera, who are showing amazing colors. The males show off their impressive sailfin during courtship. For the rest of the day they swim in a nice shoal or graze the algae from the tufastone. The wild coloured form is far more beautiful than the more commercial forms. There is no way to create a more beautiful creature than nature did. There is already some offspring in the tank. I also added Thorichthys meeki.

Water change is automatic with 3 episodes of adding 20 liters of fresh water each week by dripping system, so change in the water parameters is minimal.

Water temperature is controlled by a Eheim 3169 aquarium heater of 300 W. During the night the heater is off, to have a bit of fluctuation in temperature. Day temperature is 25°C, Morning temperature 23,5°C.
Temperature vary during the year to mimic local conditions (high variation 20-28°C).