The main difficulty in breeding oscars is their size and the size of the fish tanks needed to house them and to raise their young. Because they are cichlids they are quite picky on who they pair up with so you will need choice of partners which means buying a group of at least 6 young oscars.
Temperature for growing should be 78F and a Ph about 7. Diet can be a mix of high protein pellets and bits of raw fish, raw meat, earth worms, small live fish and frozen food.
You will need a 100 gallon tank with a gravel bottom and several large flat stones. It is better if you just use a thin layer of gravel for cleaning purposes. You will also need a second breeding tank of 100 gallons too.
You will need a powerful sponge filter. Change 25% of the tank water 2 or 3 times a week. Always siphon off any excess food.
Oscars start breeding at the age of 16 months if well cared for.
When you want the fish to breed then raise the water to 82F.
They breed an a large flattish stone or slate where there is sufficient space to lay all their eggs.
The breeding pair clean off the rock by pecking and scraping it until it is absolutely spotless.
A breeding pair will lock mouths and wrestle each other, twitch tails, nudge each other and chase away all other fish. Also their colours will become brighter.
At breeding time they become very territorial, more so than usual. They will protect the place, where they will lay their eggs, vigorously.
To help induce the fish to breed do a 20% water change with aged water at a lower temperature. Sprinkling the water into the tank will aerate it. This may induce them to start spawning.
When the pair is ready to spawn their sexual organs will bud out of their anal area. Then the pair will circle the rock and eventually the female will lay a batch which the male will immediately fertilise. This process continues until she has laid all her eggs.
Put some methylene blue in the water at this point to protect from fungal infection to the eggs.
Then the parenting begins. The pair will then fan the eggs and clean off any debris. Any unfertile or dead eggs will be eaten.
It takes 3 days for the eggs to hatch, but the fry will not be immediately free swimming. They will stick to their rock and will feed off the yolk sac that is attached to them for the next few days.
Once the yolk sac has been absorbed by the fry, the fry become free swimming. They need feeding at this point.
Now comes the hard part – keeping the fry alive.
You have to feed them 4 times a day with live food. The best starter food for them is baby brine shrimp and microworms