pH Range

Breeding and caring for the oscar fish in aquariumIdeal pH level for an Oscar fish is about 7.2, but Oscar fish are adaptable to most pH as long as the change is gradual. From about 6.0 – 8.0 is fine.

Temperature Range

Oscar fish prefer temperatures between 74 °F and 81°F (23°C - 27°C) with an ideal around 77 °F. Try to avoid fluctuations in temperature. 

Water Hardness

Soft to hard (5-20 dH)

Potential Size

Up to 16" (40cm) and over 3 pounds (1.5kg) - But usually 12”

Oscars are considered to be the most intelligent aquarium pet that you


can buy. It has an impeccable memory and can be trained to do tricks and obey its master. They come in a few different colours, the obvious black with red stripes being the most common, but other variations include a strong albino white, a pale blue and even banana yellow.
These are not community fish, unless kept with other big fish in a very large tank. Before purchasing this ‘tiny’, ‘cute’ little fish in the pet store, you must realise that they grow very big, very fast. They may start off to be a few inches but within a year they will be close to 8” long and about the size of a small dinner plate.
They are very messy eaters and constantly defeciate there digested food around the aquarium, making a huge mess. This means that you will need to do increased water changes  and also clean out the gravel quite often.
They are a lot of fun when it comes to feeding time, and you are able to hand feed them and watch them come and grab the food right between your fingers! They are not too fussy about food , but if the water conditions become somewhat not to their liking they will become unhappy and grow a pale colour.
They can also become angry and agressive with another fish in their water. They are best kept by themselves but also do well kept in pairs, 4, 5+ without too much trouble. If you do this from a young age, there may be some playful tagging as they grow up but when they are adults they will act friendly toward each other. Three, however can long-finned oscarnot be the best number due to two of the fish making a pair and then harassing the third.

pH and other qualities are of little interest, as long as you keep it closer to the neutral side of things they will flourish. It can be very hard to breed these in the aquarium unless you have a pair of older Oscars, sometimes they are easy to spawn but raising the young can be a challenge. Read below for more information on breeding.



Breeding the Oscar

Breeding Oscars is slightly harder than most other freshwater varieties. The hardes part is finding two oscars that like each other enough to spawn with each other. For quickest results you should buy an already mated and spawned pair of oscar's which will spawn every month or so.

Oscars are near impossible to tell the difference in sex. Both types look exactly the same and there is no difference in size. The only known way to tell, is to look for the small cone shaped object located around their anal opening.

If you do not buy a confirmed pair, the next safest option is to buy 6 or 7 juveniles and grow them, allowing them to naturally pick there partners. This can take time however and if your sole purpose is breeding them, possibly too much time, as it will only be when they reach 16 month of age that they are able to successfully spawn.

You are able to interbreed oscar types to come out with the most unusual colours. Reds, Tigers, Albino, Whites, and yellows can all be bred with one another. Look out for pink or purple fish as these colours arent natural.

To induce spawning behaviour keep the water clean by oscardoing 20-30% water changes every week and siphoning the gravel. Feed them a varied diet of both live and frozen foods. Crickets, meal worms and quarantined live fish work great. Do not add feeder fish from the store without first quarantining the animals as this is the easiest way to introduce disease into the tank. Frozen brine shrimp, blood worms, beef heart and prawns will also be a great compliment to their meaty diet.

The pair should show signs of mating by following a distinct change in normal swimming habbits. They will begin to slap each others tails on one another, chase each other around the tank and 'lip lock' mouths with each other. This is where it is good to make sure the oscars are around the same size or one may become agressive and try and eat the other.

When this behaviour is displayed you will need to give them some sort of spawning medium if they do not already have one, offering an upturned dinner plate is a great idea and provides the perfect surface. They will clean the surface in preparation to spawning.

The female will give birth typically 2-3 days after the mating ritual (note* if your oscars are about 12-16 months old they may show breeding behaviour but are not yet old enough to spawn) The female will give birth in batches of about 100 eggs and typically lay about 1000 in total.

There are hundreds of myths on the web saying that only 90% or so of your spawned eggs will survive. This is a load of trash, spawned eggs can have up to 90% SUCESS rate, so be prepared to have a lot of baby oscars on your hands.

The fry will hatch within about 3 days of being laid. Dont be suprised to wake up and find all the eggs gone, this is common due to a number of reasons including unfertilized eggs and spooked parents.

Your eggs may develop a cotton wool type fungus, this will only occur on unfertilized eggs but may spread to your fertilized ones aswell. Sadly there is nothing you can do about this (you may add methylne blue but it will destroy the beneficial bacteria in your tank). That is why you may see your oscar eating the infected eggs so do not be alarmed.oscar

Eggs that are fertilized will be a light brown or tan color as a pose to the white color of unfertilized eggs.

Before the eggs hatch, decide if you want to grow the babies with the adults and risk them being eaten, or move them to another tank for rearing. Choosing the latter will mean you end up with a lot more baby fish which may be good or bad depending on your needs.

If you move the eggs to another tank before they hatch be sure to use the same water from the large tank, and expect the parents to attack you when you take their eggs. Place the eggs in the new tank and leave them there to hatch.

The eggs will take about 3 days to hatch and when doing so the fry will be wagging there little tails on the rock. For the first four days they have an egg sack that they will consume and do not require feeding. After the fourth day you are able to start feeding them. You can start with insofuria but they are able to take baby brine shrimp at this time aswell. Be sure to feed them 3 times a day and remove any excess food because they need good water quality to survive.

If you leave them in the big tank, the parents will help the babies up until about 1 -1.5 inches at which stage they will think that they are food. You will need to remove the parents at this point (or the babies).

When they reach 2" you are able to sell them to your friends or stores. Good luck!


Eggs dont hatch

There may be a chance that none of your eggs hatch and this can be due to sterile fish. Over the past few years with the increased interest in oscar breeding, this problem is common and sadly there is nothing you can do about it.
These are a great fish and a lot of fun, just make sure you have at least a 2’ (55g) aquarium to support these guys.