elfchick17 asked in PetsFish · 1 decade ago

oscar tank size?

What is the tank size required for an oscar? What are some things I should know before buying an oscar? I have considered buying one for some time, but there is some skeptisism on tank size. If anyone could clear that up I would greatly appreciate it. Thanks!

17 Answers

  • Anonymous
    1 decade ago
    Favorite Answer

    I try not to comment on other people's answers. Because everybody's entitled to an opinion, but in this case, I really have to speak up about another answer since it bears such poor judgement and carelessness. WTF to the 10 gallon answer. Seriously, WTF? That's the most astoundingly wrong answer I've seen on this website, EVER. Do you even care about your fish's wellbeing beyond keeping them minamally alive for your entertainment or are you just answering every question with whatever you can pull out of your behind?

    If they weren't growing in the 10g, it was because there wasn't enough water changes to remove their growth inhibiting hormones in the water. If that's the case - then the intense ammounts of poop & waste that they emit wasn't removed either. If you're not removing the growth hormones, then you're also not doing a good job at keeping them from swimming in their own feces. That's a horrible way for an oscar to live. How would you feel if you had to live in a holding cell full of your own feces without proper management or cleaning?

    Keeping an oscar in a 10 gallon aquarium is no different than the concept of a bonsai kitty cat. Shove its head in a glass jar & soften up its bones so it will be nice & cute when you decide to play with it.

    On to my answer for the question.

    Oscars will live 7-14 years and get really big if you give them proper care. You can keep them in a smaller tank for the first year and a half or so (say, 55 gallon standard).

    After about 2 years, you'll need a wider tank, since the standard 13x48 55 gallon tank will become difficult for the fish to turn around in. (they grow to around 14-18 inches long)

    Minimum 55 Gallon Breeder tank for 1 fish (not the 13x48, but the wider less common one).with double filtration.

    Good idea would be 75 gallons tank for 1 Male oscar.

    90 gallons for a mated pair, if they're not psychopathic killers (which some are), which may be cutting it short by some people's standards. You can try, but it depends on their personalities.

    125 gallons + for a pair if they are psychopathic killers. Possibly more, but many people can do 125 gallons. They can get bitey with each other in 125, but most of the time it works out.

    During adolescnce, your oscar should grow about 3/4 of an inch per month. The issue of the fish's large size is compounded by the fish waste emitted by the oscar. Oscars are messy eaters, often spitting out a lot of food and letting it go to waste. They poop a lot, and as such are one of the top fish for waste production. Even if they physically fit in the tank, it may not be adequate enough to support a robust bacterial filter to keep everything stable during water changes.

    If you're concerned about the cost of a tank, I reccommend your local craigslist. Often times you can get a good size of tank for 1/4 the cost of a new retail one from a chain store. If you want to roll up your sleves, you can also buy tanks that need re-sealed. I got a 90 gallon tank on craigslist for $110. 2 tubes of caulking were $10 & the stand was $140 for an oak one at my local pet supply warehouse.

    The overall theme of keeping oscars, is to buy as big of a tank as you can afford... They grow big (but not to unmanageable sizes), and they will use all of the tank that you can get them.

    If you can't afford a big tank, you shouldn't get an oscar. They can grow faster than you expect, and there are other smaller species, such as convict cichlids that can provide similar entertainment.

  • Anonymous
    1 decade ago

    Oscars get large and I don't recommend them for anything smaller than a 75 gallon aquarium. You can put 2 adults in this size aquarium and they will be fine. A lot of people will use a 55 gallon for Oscars or similar sized fish though the depth (front to back) of a 55 is only 12" and eventually the Oscars gets too large to turn around in this size aquarium. A 75 gallon is 18" front to back and is therefore acceptable. The minimum floor dimensions I would recommend are 4' x 1 1/2'. The height isn't as important though these are large messy eaters and your filtration needs to be a lot stronger for an Oscar than many other fish of equal size. If you want to breed these start a 75 gallon or larger with 5 fish small Oscars and as they get larger (though are still small enough to handle this number of fish in the aquariuum) 2 of them will pair off and all of the rest of the fish will be in the opposite corner. That's when you call some friends and let them know you have 3 Oscars to get rid of. If they are still small when they are breeding you may be able to keep the other fish in the aquarium together though eventually and this is fairly quickly you will need to only have 2 Adult Oscars in a 75 though you can have more based on the size of your aquarium.

  • 6 years ago

    In recent years bow front and cube aquariums have become a lot cheaper. In some cases the same price as a normal rectangular tank. These are much better for Oscars because it allows for more turn around room. This is really the biggest issue when getting a tank for your oscar. In bow front 55 gallon tanks or a cube 45 to 55 gallon tank your oscar will be fine and live a much happier life. (With the correct filtration and water changes.)

  • 1 decade ago

    you need a big tank. The bigger the better. For one oscar, you want a minimum of 55 gallons, but 75 is better. If you want two oscars, I would go 100 or more. They do grow fast and they get huge!! Some people think its ok to stuff a baby oscar in a 10 gallon....this is never a good idea.-- They are cool fish. Feeding time can be a bit messy when they get bigger. You will want to keep up with regular water changes too. oh, and they can jump out of the tank if you leave the lid open! Just some things to watch for.

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  • 1 decade ago

    Bare minimum for an oscar by itself is 55 gallons, but I do believe a 75 gallon is better. I know the one I had grew to about 14 inches. As Patrick said, not much turning room in a 55 gallon for them.

    For oscars, over filter the tank. For a 55 gallon, I would run at least 2 filters, preferably one a canister filter, and have a minimum of 1000 gph in filtration.

    One of the most important things for these guys, vary their diet. Once or twice a week I would also soak some of his pellets in a liquid vitamin, I just used the childrens Poly Vi Sol. Good pellet food, cut up pieces of cocktail shrimp and squid, frozen/thawed beefheart, worms, etc. just stay away from feeder fish.

    Frequent water changes are a definite must with them. Want to keep the nitrates ideally under or around 20 ppm. High nitrates can lead to hole in the head disease for them. For awhile I had mine in a 55 gallon, had good filtration, and was still doing 2 water changes weekly of about 50-60%. Here's a great site with lots of info on oscars:



  • Pamela
    Lv 4
    5 years ago

    For the best answers, search on this site https://shorturl.im/axJeJ

    ive done a lone oscar in a 55 gal before. and from that experience, i wish i went with a 75. even with a rena canister filter and weekly cleanings (couldnt keep a plec in there so i had do de-aglaefy the tank myself) he still dirtied up the tank pretty well. not saying the 55 is a bad choice, just the 75 would have given a little more breathing room for the guy (and me, probably couldve bumped cleanings up to a week and a half at a time)

  • 1 decade ago

    Oscars require a minimum 70 gallon tank.

    Here is more information about some of the various Oscars that I found that may help you out.

  • 1 decade ago

    Oscars need a much bigger tank than 10 gallons! They grow very large (up to 1 foot long) and are dirty fish. One oscar needs about 50 gallons, and good filtration. Oscars also like to dig into their substrate and uproot any plants, so planting live plants will be more frusterating than anything. I think that a ~50 gallon tank, with minimal decoration and a strong filter would be a good setup for 1 oscar

  • luptak
    Lv 4
    4 years ago

    Cube Aquarium Sizes

  • Anonymous
    1 decade ago

    ok .... an adult oscar will be ok in a 55 gallon tank but will reslly be happy in a 75 gallon tank.... note that this is the tank size required for ONE full grown oscar..

    oscars are amazing fish bcoz of their response to its owners. they are known to have strong personalities and can even"play" around with people.... they require large, heavily filtered tanks at a temp range from 24* to 28*C .... they need varied diet consisting of brine shrimp, cichlid pellets, cichlid sticks, tubiflex worms , freez dried worms etc...... variety is the key to a healthy oscar..... further more u shd know abt the different varieties of oscars..... all have similar temperment but differ in colour...

    ALBINO OSCAR, TIGER OSCAR, RED OSCAR........ these are ones that u want to look at........ however, 3 full grown oscars will do nicely in a 150 gallon aquarium.....

    for further reference try


    amazing site.......

    hope tis helps!!!!!!!!!

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