While it is possible to keep trout in an aquarium they are certainly a challenging fish to keep alive. Trout require large (200 gallons minimum), chilled tanks filled with clean, highly oxygenated water ideally with current. Trout are large fish that like to jump. They are not easy to keep in aquariums and beginners should probably start with an easier species.
Like most fishermen, keeping a few trout in a tank has crossed my mind. Who does not want a few pet trout?
But I found the resources online to be quite lacking. As someone who writes about trout every day, I quickly realized that most of the articles on keeping trout were written by people who do not understand the species well.
So mostly for my own interest, I decided to combine my expertise in trout with knowledge from experience aquarists to write this guide on what to expect when keeping trout in an aquarium.
How much will a trout aquarium cost?
Trout are expensive pets to keep.
The most expensive three purchases will be the tank, the filters, and the chillers.
It will be easy to spend in excess of $3000 for a basic 200-gallon tank including the stand. Higher quality setups will cost more. Some money can be saved by constructing your own stand.
Trout tanks require a lot of filtration, it is not an area to save money. This could set you back another $1200
A chiller capable of cooling a 200 tank will likely cost in the range of $700-900,
Finally, there are all the pumps, powerheads, spray bars, piping lightening, substrate, etc. While not expensive individually they do start to add up so maybe budget another $600.
The ballpark figure for the establishment of a 200-gallon coldwater trout tank is around $5600
Then there are the ongoing expenses to operate and maintain the chiller, filters, and pumps. While most of the pumps and filters only cost dollars per month, the chiller is like running a small air conditioning unit, so when running hard it can easily cost over $100 per month.
What species of trout is best to keep in an aquarium
While all species of trout are challenging to care for, brook trout should cause fewer problems if tank space is limited.
That is because brook trout rarely grow larger than 10lb. That is significantly smaller than Brown and Rainbows, both of which can exceed 30lb.
One downside to brook trout is that they are less tolerant to warmer temperatures than brown or rainbow trout. So temperatures need to be kept slightly cooler. Rainbow and brown trout are also slightly more tolerant to dirty water.
It is also highly advisable to avoid mixing species or age groups of fish because the more dominant ones are likely to bully others when in a confined space.
What size tank for trout?
Trout will not thrive in a small tank, and as they grow their demand for space only increases. While young trout can survive in a small tank they quickly outgrow it.
It is generally advised not to keep trout in aquariums smaller than 200 gallons (900L). This might sound like a large tank, and when full it is certainly too heavy for a single person to move, but it is still under a cubic meter, or 35 cubic feet in size. A fully grown trout does not have much room to turn around.
If you are serious about keeping multiple trout consider a custom-built 1000-gallon tank. A tank of this size provides plenty of space for several trout to mature into.
What temperature of water do trout require?
Trout are cold water fish, they will happily survive in water close to freezing, but will struggle and might even die if the water consistency exceeds 68f. For a home aquarium, it is generally advised that the water temperature in the aquarium is maintained between 54-58F. Colder temperatures over winter are fine.
Maintaining temperatures this low requires the constant use of a chiller unit. The larger the tank, the more powerful the chiller needs to be. A 200 gallon tank typically requires a 1/4hp unit, but in warm climates, a more powerful unit might be required. While I have no direct experience with them the JBJ Arctica Aquarium Chiller has a good reputation and is widely available. Although, like all quality aquarium products it is not a budget option.
How to maintain current in a trout tank?
When living in an aquarium trout require a strong current to swim against. This allows the oxygenated water to flow through their gills while the trout rest in place.
The most common way to generate a current inside a tank is by using powerheads.
In a still water pond and lake, they have plenty of room to cruise, but in a space confined aquarium, they need to swim into the current. A trout can not be expected to swim laps all day and stay healthy.
Maintaining oxygen levels in a trout tank
Trout require high oxygen levels, so it is essential for their well-being to add supplementary oxygen to their tank. Surface transfusion (gas transfer) can not be relied upon. In the section below I will list several ways to increase the oxygen levels in a tank.
Multiple methods working in harmony are ideal.
- Aquarium bubblers: I think we have all seen bubblers, they attach to an air pump that produces a steady stream of bubbles. They come in many sizes, shapes, and designs. Powerful bubblers can be a bit loud so are not always the most popular option.
- HOB filters: These filters are installed on the back of the aquarium where they release filtered water back onto the surface. This in turn agitates the surface area creating a greater area for gas exchange to take place.
- Spray bars: work in a similar way to Hob filters. They sprinkle water from the filter outlet onto the surface of the tank agitating it.
- Powerheads: are an essential component of a trout aquarium. They are used to create a current which flows through the aquarium. This current better distributes oxygen rich water from the surface throughout the tank.
Trout tanks require the use of a high capacity aquarium filter. Models such as the Fluval FX5 or Eheim Series with 2 or 3 units combined together complete with a sump system are often required to sufficiently filter the water to maintain fish health.
Trout typically require more filtration per volume of water than more typical aquarium fish.
If you are unsure whether you are providing enough filtration capacity, it is generally better to have too much filtration rather than not enough. For more in-depth advice, I suggest consulting the local fish specialist store or filter manufacturer.
How long can a trout survive in an aquarium?
The life expectancy of a pet trout largely comes down to the ability of the owner to keep conditions suitable. Most trout die due to user error within a few days of being introduced. They are not a beginner friendly fish.
If the trout do not die from mistreatment, you can expect your trout to survive for at least 5 to 6 years. Because aquarium trout will likely never go through the stresses of migrating and spawning, they can live much longer than fish in the wild.
Where to source trout for an aquarium
The best place to source a pet trout is by purchasing one from a local hatchery.
This may or might not require a permit and the details of which need to be checked with the appropriate authorities. Although, the hatchery staff will probably be up to date with the regulations.
While it might be tempting to catch and keep wild trout, they are unlikely to survive the transition to life in a tank. Transferring wild fish is also illegal in many states.
Hatchery trout are also much easier to care for, because they readily eat hatchery pellets, and should be free of disease and infection.
What to feed trout in an aquarium
It is generally advised to feed trout a high quality fish pellet comparable to the feed they get in hatcheries. It might be possible to source fish pellets directly from the hatchery you brought the trout from, failing that bags of trout pellets are generally available to buy online.
It is important not to overfeed your trout. Life in an aquarium is very Stationary, and overfeeding can lead to obesity and a rapid growth rate.
Some very serious hobbyists might want to try and raise the trout’s natural diet as a supplement to the pellets. It is actually possible for mayfly and caddish nymphs to become established in large aquariums and the nymph’s grazing can assist in algae control.
As a treat, also consider feeding the trout the occasional live worm or cricket. These can usually be purchased from pet shops.
Substrate – The stuff that goes on the bottom of the tank.
Smooth pebbles are probably the best choice for a substrate of a trout tank. They are fairly chemically inert and heavy enough not to be blown around the tank by the powerheads.
Some people ask if is it possible to use river source gravel as a substrate, but this runs the risk of introducing unwanted pests such as algae, and in extreme cases, it can even bring diseases into the tank.
Some river pebbles, especially if they are high in calcium can also raise the PH of the tank. If the water is natively acidic, this might be desirable but in most cases inert pebbles
cause fewer headaches.
Water Quality and Parameters For Trout
As I mentioned earlier in this article. Trout are high maintenance fish that require a large amount of care.
The water must be kept very clean so filtering on a regular basis is required. The water should be turned over at least 10 times every hour.
Aim to change about 25% of the tank water every week. This is slightly more than average, but trout are not hardy fish in aquariums. This will assist in keeping nitrate levels low.
It is also important to note that chlorinated tap water is dangerous to the health of an aquarium.
When a tank is new, it is advised to test for the following parameters every few days. Once conditions have stabilized, weekly testing is sufficient.
Testing might seem daunting, but it is quick and cheap and easily done at home. I recommend consulting with your local pet store, or purchasing an API Master testing kit and following the included instruction. Such kits include almost everything you’ll need to run these tests.
- PH: neutral or slightly alkaline (pH 7-7.5) and of moderate hardness (dH 10-15).
- Ammonia: Target level: 0
- Nitrite: Target Level: 0
- Nitrate: Target level: 10ppm or less
- Phosphate: 0.05ppm or less