Are you concerned that your oscar fish is not growing? They can grow quite big, but why is yours not? In this article, we’ll discover if something is wrong with your smaller oscar fish.
Why Is My Oscar Fish Not Growing? A small tank, insufficient feedings, illness or genetics can all play roles in smaller oscar fish. If your oscar fish is healthy, do not be concerned. Consider more food, more space and increasing water changes.
How Big Should My Oscar Fish Grow?
- Juvenile oscar fish: 1-3 Inches
- Average growth after year 1: 6-10 inches
- Average size of mature oscar fish: 12-18 inches
An oscar fish is usually sold in a local pet store as a juvenile fish. At this point, in their first year, they will start at about 1-3 inches.
Oscar fish tend to grow rapidly in their first year. You may notice a growth spurt that bring them to 10 inches or more by the end of the first year.
Some oscar fish have been spotted at 16-18 inches and weighing over 3 pounds. This could be due to their genetics, larger swimming space or being fed large amounts of food.
There are some oscar fish who may dwarf in size or be considered runts due to their lack of growth. If these smaller oscar fish continue to eat almost anything you feed them, they are quite normal in their habits and behavior.
A smaller oscar fish that doesn’t grow is rare. Consider yourself lucky to have one if it is healthy.
How Do I Tell If My Small Oscar Fish Is Sick?
Oscar fish could get bladder diseases or parasites like many other fish. If they stop consuming at the rate they normally eat, they’re growth will be stunted.
If your oscar fish has been through illness or stress at an early stage of its life, this may have impacted its growth. The growth slows down immensely after their first year.
If your oscar fish is sick or stressed, you can tell from multiple signs:
- slow or lethargic
- weakened swimming
- laying on its side
- discoloration
- lack of appetite
- distancing itself from other fish
- bloated stomach
Do Oscar Fish Stop Growing After One Year?
The first year in the life of an oscar fish is one that demonstrates massive growth. If you aren’t witnessing your oscar fish growing up to 6-10 inches in their first year, then you might be concerned.
A stressed or sick oscar fish in its first year may limit its growth potential. If the oscar fish recovered and is now healthily swimming and eating, then there is no problem with having a smaller oscar fish.
Oscar fish will continue to grow in their sceond year by about 2-3 inches. At full maturity you may see your oscar fish reaching 12-16 inches on average.
Is My Tank Too Small And Not Letting My Oscar Fish Grow?
A smaller tank could be culprit to the stunted growth of an oscar fish. Not all oscar fish are created equal. We are told that a 70-75 gallon is more than enough room for an oscar fish to live a healthy life.
Unfortunately, that is not the case for all oscar fish. We are talking about fish that can grow up to 18 inches in their natural environments. A 100 gallon tank or larger will help replicate the space they may require to further grow.
The more they swim in a larger tank, the more energy they burn. This will cause your oscar fish to want and eat more food. The result may lead to a larger oscar fish.
- 1 oscar fish: 50-75 gallons
- 2 oscar fish: 75-100 gallons
- 3 oscar fish: 100+ gallons
What Can I Do To Help My Oscar Fish Grow?
- A larger tank
- More food
- More vitamin supplements
- Increase water changes
- Decrease Stress From Tankmates
- Consider medicine for parasites
How Much Food Can I Feed My Smaller Oscar Fish?
You can feed your growing oscar fish every 2-3 hours. If you feel their growth is stunted or too slow, feed them often. Every 2 hours is a lot of food for the average fish, but most don’t grow as fast as an oscar fish in its first year.
Add more protein in their diet from live or frozen food such as shrimp, worms and insects. If you feed too many peas, they may spend more energy digesting it rather than using its protein for growth.
Once your oscar fish grows beyond 4-5 inches, you can slow down the feedings. Make sure you aren’t overfeeding by checking for bloating or constipation. Clean the tank more frequently with the added food creating more waste.
Could My Smaller Oscar Fish Have Parasites?
You will notice that your oscar fish is lethargic or lacking an appetite. They could show signs of a parasite affecting their growth.
There are products on the market to assist with parasites in oscar fish. Prazipro in a bottle is one such medication used for freshwater fish to treat parasitic infections.
Consider more research or a second option before applying this medication. Always read the instructions carefully on the bottle.
Do Water Changes Help Oscar Fish Grow?
Many fishkeepers will suggest increasing water changes to promote healthier growth patterns in oscar fish. 25% water changes every week is a good start to help your smaller oscar fish.
Nitrate levels are lowered by water changes better than filtration. If you’re very concerned about the slow or stunted growth of your oscar fish, consider 50% water changes twice a week.
Nitrate levels below 20ppm is good, but with frequent water changes, you can get it down to 5ppm. This could help promote a healthier environment for your oscar fish to grow faster.
Is My Oscar Fish Small Because Of Bullying?
Some oscar fish or other tankmakes may express their dominance over others. If your smaller oscar fish has been bullied by its tankmates, then it could also stunt its growth.
Dominant fish tend to be larger than the ones they are bullying. A smaller oscar fish could be a victim of bullying. Separating the tankmates and noticing an improvement in its eating habits and growth is also an option.
Conclusion
Oscar fish are rather large when they reach full maturity. 16-18 inches in the wild may not replicate itself well in an aquarium at 100 gallons or less. Consider a larger tank, more feedings and lots of water changes to help promote the growth of oscar fish.
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