If you plan to have more than one Oscar, you’ll need at least 120 US gal (450 L) instead.
If your aquarium didn’t come with a lid, write down the exact measurements of the width and depth, then visit your local aquarium supply store or pet shop.
If the water is too cold, it can suppress your Oscar’s immune system, leaving them vulnerable to illness. If it’s too warm, it can deprive the fish of oxygen, which can lead to nerve and heart damage. [4] X Research source Oscars will often destroy a thermometer placed inside of their tank, which is why an external thermometer is recommended. Check the manufacturer’s information to ensure you choose the right heater for your size tank. [5] X Research source
Avoid sharp or rough decoration, as they could injure the Oscar if it gets startled and darts around. Choose heavy decorations if you don’t want the Oscar to move them.
Keep in mind that since Oscars will dig in the substrate, it’s important not to use anything sharp, as this could injure the fish. If you don’t want to, you don’t have to include a substrate at all. Just clean the bottom of the tank occasionally, as any debris that settles will be visible.
A water filter will help prevent the buildup of ammonia in the tank. Too much ammonia can stress the fish, causing them to lose their appetites and their color to fade. [8] X Research source Choose a filter that is rated higher than the capacity of your tank. For instance, if you have a 75 US gal (280,000 mL) tank, you’d want at least a 100 US gal (380,000 mL) filter.
For example, if you have a 100 US gal (380 L) tank, you would change 10–15 US gal (38–57 L) each week. This is a gentle way to clean, since it maintains the environment that the fish are used to.
If the pH is too low, or the water is too acidic, add 1 tsp (7 g) of baking soda for every 5 US gal (19,000 mL) of water. [11] X Research source If the pH is too high, or the water is too basic, place a clump of peat moss in a mesh bag and place it inside of the water filter. You can buy clumps of peat moss at an aquarium supply store. [12] X Research source
If your Oscar is already mature, try moving the fish to a new tank when you introduce them. That way, neither one becomes territorial. You can provide 1 tank mate, or you can keep Oscars in groups of 4 or 5. However, avoid having 3 Oscars in a tank, since 2 might bond with each other and leave the other one isolated. [14] X Research source
To ensure your Oscar gets all of the vitamins it needs, choose a pellet that also contains algae or green plant material. Nutritional deficiencies are the cause of the most common oscar illness, which is known as “hole in the head disease” due to the abscesses that form on the fish’s head and body. [16] X Research source
Bloodworms, feeder shrimp, krill, crickets, and mealworms are all popular options for feeding Oscars.
If you’re not sure how much your fish will eat, drop in a few pellets and wait for the fish to eat them, then drop in a few more. Continue this for about 3 minutes. Once you get a good idea of how much your Oscar eats at each meal, you can drop it all in at once.
Not only do feeder fish lack the nutrition your Oscar needs, they can actually create additional problems. For instance, feeder goldfish contain high levels of an enzyme that will destroy the vitamin B1 in your Oscar’s system.
Females have a cone-shaped tube near their anal fin, known as the egg tube. However, this stays retracted most of the time. Males have a thin spike, which they use to fertilize the eggs.
Do this at the same time as your normal weekly cleaning to avoid changing too much of the water at once, since you don’t want to stress the fish.
Don’t drop the temperature any more than this, or you could shock your fish.
You can find spray bars wherever aquarium equipment is sold.
You may even be able to see the female laying eggs across the bottom of the tank!
Don’t be alarmed if you see the pair eating some of the eggs. They do this to remove deformed or unhealthy eggs from the batch. Right before the eggs hatch, you may see them shaking slightly as the fry try to break free.
Remove any uneaten food from the nursery before you feed the fry again. Once the fish reach about 1–2 in (2. 5–5. 1 cm) long, they’re ready to find a new home!
