Plecos are a type of fish that can thrive in both heated and unheated tanks. If you plan to keep them in an unheated tank, it is important to ensure the water temperature remains stable. This means avoiding sudden changes in water temperature as this can be very stressful for the pleco. They prefer a pH level between 6-7 and temperatures between 68°F – 79°F (20°C-26°C). It is also important to provide plenty of hiding spaces with driftwood, rocks or caves so they feel safe at all times. Additionally, providing plenty of algae as food will help keep their diet balanced. Lastly, regular water changes are necessary when keeping plecos in an unheated tank; 10-15% weekly should suffice but could vary depending on your setup.