Setting up an Oscar Fish TankBefore rushing out to buy your first Oscar take some time to look at what is involved in keeping one of these fish. Surprisingly, Oscars can live for over 10 years, that's the same as a pet dog. So it's important that you understand that getting an Oscar is a long-term commitment to looking after your fish's welfare. Your Oscar is going to rely solely on you to make sure that it's home is clean and safe at all times. Your commitment to your Oscar will mean carrying out tank maintenance at least once a week for the entirety of your fish's life. Changing water and cleaning substrate shouldn't take more than one hour every week, but it will be a task that cannot be overlooked or ignored.
Aquariums cost money to runYou should consider the cost of keeping a large aquarium running 24/7. You will need a heater and a filter running every single day of the year. Because Oscars are tropical fish the aquarium water must be kept warm at all times. A 55-gallon aquarium is going to require a minimum of 200 W of heating that must be switched on all the time (imagine leaving the house lights on 24/7 in two or three rooms of your house). Filters won't use as much power, but they will still need to be kept running at all times. Many of us have water meters and therefore pay for what you use. The bigger the tank, the bigger the water change each week. Then you've got your food on top of all this, plus any medication that may be needed. The biggest mistake you can make is thinking that an aquarium doesn't cost anything to run. Big aquariums can not only increase your electric bill each year, but also the water bill at the same time.
The correct size aquarium
Aquariums come in many shapes and sizes. When choosing a tank for your Oscar you should opt for a tank that will allow the Oscar to swim back-and-forth quite easily. Therefore, avoid dome and hexagon -shaped aquariums, they don't have enough length in them to allow the Oscar room to swim freely.
If you are buying from the fish store then they will be able to tell you exactly how many gallons the tank holds. However, if you are buying second-hand then it's not always apparent how many gallons the tank holds. Using this simple aquarium size calculator, you can enter the dimensions of the tank and it will give you an accurate reading of exactly how many gallons/litres the aquarium holds.
Always use a secure aquarium hoodI really can't emphasise enough how important it is that you have a secure lid on your aquarium if you are keeping Oscar fish. For some reason Oscars like jumping. I believe that in the wild they will often jump out of the water to catch insects from overhanging leaves and branches. They seem to replicate this in the aquarium as I've seen them jumping out of the water to catch small flies. Even a medium-size Oscar can lift the lid a couple of inches on a 125-gallon aquarium. Some tanks don't have lids, they just have the lights suspended above the water. These are most definitely the worst design aquarium you could ever use with an Oscar. If you want to avoid finding your Oscar dried up on the floor in the morning then always use a secure lid on your fish tank.
The importance of good filtration
Knowing how your filter media worksI think it's important that you understand what's inside your filter and how the different elements work to keep your water clean. All filters come with mechanical and biological filtration, some also contain chemical filtration. All three types of filter media have their own job to do and knowing what each one does is very important.
normally comes in the form of a piece of sponge, often blue in colour. This type of media is there to catch any solid pieces of debris that the filters suck up. The debris can be anything from fish poo through to uneaten fish food. Depending on what size tank you've got, and how many fish you are keeping will determine how often you will need to remove the mechanical filtration for cleaning. Cleaning mechanical filtration is very straightforward, you can take it out of the filter and give it a rinse out in a bucket of existing tank water. This type of mechanical filtration can be changed every few months when it gets absolutely filthy. .
is what really keeps the whole aquarium alive. It's what removes all the toxins from the water and keeps the fish alive. Without biological filtration your fish would be swimming around in a toxic soup. If you are using a canister filter then you will probably find it came with some strange -looking bags of material that either resembles little round balls, or little rings that look a bit like pasta. This in fact is your biological media and will be contained within the trays in the filter. This type of filter media is very porous and therefore the nitrifying bacteria have a really good surface to live on. The big advantage with using this type of biological media within a canister filter is that it really does an excellent job of dealing with ammonia and nitrite. Secondly, if you don't overstock your aquarium then you can often leave canister filters for longer intervals in between cleaning.
Chemical filtration (activated carbon)
You may have noticed a black sponge in your filter. This is what is called chemical filtration and it's designed to remove impurities from the water. The best use you can get from using chemical filtration is to remove any medication that is left over from a water treatment. Some people use it in order to stop their water smelling. However, the problem with chemical filtration is that eventually, it will become completely saturated with impurities. If this happens then there is a possibility that impurities could start leaching back into the aquarium water. It's up to you whether you use chemical filtration. If you do use it then be aware that it needs replacing every few months.
Which filter to useThere are only two types of filter I would recommend for an Oscar fish aquarium, and they are a large canister filter or a sump filter. Because Oscar fish require large aquariums, small filters are of little use because you would need about three or four of them installed in the aquarium. Even then, you probably wouldn't have adequate filtration. There are numerous different manufacturers of canister filters that would do a great job in your aquarium. If you've got the money then I would recommend Eheim as they produce the Rolls-Royce of aquarium filters. Yes, they are expensive, however, you get exactly what you pay for. Eheim produces canister filters that will filtrate aquariums right up to 1200 L, which is about 300 gallons. I've used Eheim filters ever since I got my first aquarium and I think they are just fantastic. Another make of filter that a lot of people highly recommend is Fluval. They also produce good quality canister filters that are more than adequate for filtrate in a large aquarium containing Oscar fish. Because Oscars are so incredibly messy it's a good idea to literally double the filtration on your aquarium. If you've only got the one adult Oscar in a 55-gallon aquarium then I don't think there's any need to go over the top, a filter rated for a 100-gallon aquarium would work just great. When I had my 125-gallon aquarium I have a couple of Eheim 2028 canister filters installed, both of which are rated up to 132 gallons. But I had two Oscars and a few tankmates and the extra filtration was well needed. The beauty of having two canisters installed on the one aquarium is if one breaks down, you've still got a working filter that will still keep the tank clean until you get the other one fixed. Also, having to filters means that you can alternate filtration cleaning. This means that you are not cleaning both filters at the same time risking losing bacteria. You can clean one filter one week, and then wait another week and do the other one.
Keeping oxygen levels upCanister filters normally come with a spray bar that resembles a garden sprinkler. The spray bar is attached to the side of the tank and should always be placed just above the surface of the water. What you are aiming to achieve is a constant water surface movement created by the water spray. It's important that your fish have plenty of oxygen, setting up your spray bars properly will create this surface agitation and in turn creates lots of little oxygen bubbles. When a fish tank hasn't got enough oxygen in the water the fish will normally breathe fairly heavily. If the oxygen depletion is particularly severe then the fish may hang at the surface opening and closing their mouths whilst they take in oxygen. If you're using a good filtration system then it should oxygenate the water properly. However, if you feel that you want to add oxygen to the water, maybe because the weather is warm then you can use an air stone.
The sump filterFor fish keepers who have got especially large aquariums, the sump filter is often a good alternative to a canister filter. As I've already mentioned Eheim do produce a canister filter which is capable of filtering a 1200 L aquarium which is approximately 300 gallons. However, once you start getting even bigger, four or 500 gallons then a canister filter is just not going to be efficient enough. The beauty with sump filters is they are relatively easy to make and you can make them as big as you like. We have a page dedicated to the workings of the sump filter so have a read. Further Reading on Sump Filters...
Heating your aquarium
Aquarium thermometers were always the bane of my life, I never found an internal thermometer that the Oscars wouldn't find and destroy. The best advice I can give you is to completely forget about putting thermometers inside the tank, you'll be wasting your time if you've got Oscars. The best thermometers I have used are external and therefore out of the reach of destructive Oscars. You don't have to pay a fortune, you can get one for £10 and it will last you for years.
Oscars do not require any specialised lighting, in fact, you could probably leave the lights off all day and it wouldn't bother them in the slightest.
However, we have all gone to the trouble of setting up an aquarium so it's obviously nice to be able to see what's going on. It's even nicer if you can use lighting that brings out the colours in your fish, although many Oscars are rather dull and drab. Having said that, lots of tropical fish do have beautiful colours that can be wasted if the aquarium lighting isn't very good. use the Kelvin rating, this is basically the colour temperature of the light, the full spectrum of light produced by the sun which consists of different wavelengths. I know, pretty boring and not really that interesting to talk about unless you are an aquarium lights enthusiast.
The best advice I can give you is to think about what type of lighting you want to achieve. Most people want to see their fish properly, may be the colours popping. Therefore depending on how many bulbs your system takes, you could opt for one Marine blue and one Marine white. Maybe you've got a large aquarium which takes three bulbs, you could opt for two Marine blue and one Marine white, or vice versa. It's impossible for me to tell you exactly what you need, the best thing to do is go to the fish store and see what's available, I'm sure they could give you some really good advice. Alternatively, come and talk to us on the forum and somebody will be happy to advise you on lighting.
Sand and gravelI think aquariums looks completely bare without substrate. I know a lot of people claim that the aquarium stays cleaner without substrate, but I like my fish tanks to look like a small part of the wild. I've used both sand and gravel over the years, however nowadays I tend to stick with the sand. The most common type of sand people use is pool filter sand which you can get from hardware stores, garden centres and probably your fish store as well. Is always a good idea to give your substrate a swill and a bucket of water, even if it looks clean. Gravel will often contain a lot of fine dust which won't cause any harm to your aquarium, but it will make you very cloudy initially. You don't need to put too much substrate in your tank, about an inch and a half in depth is more than enough. The problem with putting too much substrate in an aquarium is when it comes to cleaning, especially gravel, it's sometimes difficult to reach right down to the bottom where some of the dirt and debris collect. If you keep substrate fairly shallow then you should be able to remove that a lot easier with a vac. You can purchase special substrate cleaning tools that make it easy to clean the substrate. These normally consist of a long pipe that connects to your tap. The Python is one such gadget that does work very well if you have a strong water flow. However, it uses water in order to remove water from the tank. So if you're on a water meter I would not recommend this piece of equipment. For years now all I have used is a bog standard hosepipe with a Vac attachment on the end. I just stick the end out of the window, get the syphon going and it works as good as any £55 Python. Cleaning sand takes a little time to get used to. What you don't want to do is suck it all up through the pipe. So what you do is just hover the Vac about an inch or two above the sand and suck all the bits of debris up. Gravel, on the other hand, is the complete opposite, you need to push the Vac head into the gravel and then wait for the gravel Vac to run clear.
Aquarium woodWood is a great addition to an aquarium, especially the great big pieces that you can get. However, wood isn't always cheap, especially if you want a really big piece. You can pay over £100 for the really large pieces of wood. But in my opinion, they really do look the business. It's important that you be extra careful when deciding on adding wood to your aquarium. Don't put wood that you find on the beach, or in the woods in your aquarium because it probably won't be cured properly and the chances are it will just go rotten once submerged under the water. My advice would be to buy properly preserved wood that is completely ready to go straight into an aquarium.. Be aware that some types of bog wood can stain the water and turn it a yellowish in colour. Some people like to boil wood before putting it in their aquarium so that if there is anything nasty present they can eliminate it.. When you first put wood into your tank you may find it floats. Don't worry about this, it will soon become saturated and sink to the bottom. Alternatively, you could always attach a few weights to make sure that it sits properly on the bottom of the tank. I like to place my wood near the back of the tank, rather than too close to the glass. You'll find that fish such as plecs, loach, catfish and smaller tank mates appreciate the extra shelter and protection that large pieces of wood offer..