Maintaining stable water temperature is vital to aquarium health
Figure 1. Time course temperature of aquarium water and a coral beneath a high wattage lamp. These are with 'good' water flow.
So you've went out and bought some fish and the store told you to acclimate the fish by floating the bag in the tank for 15 minutes and then release them into your aquarium. Right? Wrong! The only thing floating the bag accomplishes is that it brings the water in the bag closer to the temperature of the water in your tank. We need to be concerned about more than just temperature. The aquarium water chemistry is just as important as the temperature when it comes to acclimating fish.
Performing a water change with cooler water will help by lowering the temperature and introducing fresh oxygen. Heaters should be turned off, as well as lights. Remove the aquarium cover and blowing air across the surface from a fan will also help cool the water. It is wise to place a piece of screen over the top to keep fish from jumping out. A few ice cubes placed in a zip-close bag can be placed in the tank to help keep the water cooler.
Aquarium Temperature Management: Prevent a Warm Water Disaster
Water Temperature in the Aquarium - Aquarium Adventure Columbus
Oscar fish come from the tropics and therefore need to live in a heated aquarium. Oscars are okay with a water temperature as low as 21°C, and they can cope with temperatures of up to 30°C (temporarily I should add). A good temperature for Oscars all year round is 27°C. Oscars are known for being fairly rough with things that are placed inside their aquarium. For some strange reason, they often take a bit of a dislike to heaters and can easily smash a glass heater to pieces. Over the years I've had to replace the heater several times because of destructive Oscar fish. There are loads of heaters on the market that are made of heavy duty glass or even metal. These are the type of heaters that I would recommend for an Oscar fish aquarium. One of the best heaters I ever used was manufactured by a company called Aqua Medic. They manufacture single heaters up to 500 W which is perfect for aquariums up to around 125 gallons. They are made of titanium and are virtually indestructible, the Oscar would have to be on steroids to even make a dent in one of these heating elements. However, you also have to purchase the control box that goes with these heaters so they will end up being quite expensive. If you would prefer something a little more affordable than you could look at a new range of heaters called SCHEGO. They are also made of titanium and are extremely robust. Like the Aqua Medic, you also need to purchase a temperature controller because they don't have a built-in thermostat. However, the thermostat that controls the SCHEGO range of heaters is a lot cheaper than the Aqua Medic model. Your heater should always be submerged under water. I always like to place mine near to the water flow entering the aquarium. This will ensure that the whole aquarium is heated properly. One important thing to bear in mind is using the correct size wattage for your size of the tank. What you don't really want happening is the heater working overtime in order to keep the water warm, this will just cost you an absolute fortune and will probably lessen the life of the heater.The easiest way to maintain the correct water temperature in a turtle tank is by using one or more aquarium heaters. These are commonly available in pet supply stores, but you have to be careful to choose the right heater. There are two things that you have to consider.