Same Day Dispatch Ends In

Free Delivery

On all orders!

Earn Reward Points

Just register at checkout.

60 Day Returns

Shop with confidence.

Finance Available

Including Pay Monthly & Pay Later

Your Cart

Total £0.00
Checkout View my Cart

Fish Compatibility

Lion Fish

Having your own marine fish tank is a popular choice for many people starting out in the world of fish keeping, or those with some experience already, because most varieties of marine fish have similar requirements for their environment. There are a wide range of sea creatures that can happily exist in the same conditions as long as the water is at the right temperature and they have the right food available, plus there is the added bonus that many of these marine creatures are amazingly colourful and diverse. So why not have a marine tank full of different and interesting pets?

Unfortunately, many of these marine fish aren’t suitable to keep together in the same tank, even if it’s large enough and warm enough. For many reasons you might not realise at first, fish have different social needs, different behaviour and different predators that make some combinations a disaster waiting to happen. Unlike freshwater fish, a high proportion of popular marine species are very aggressive and territorial, so it’s important to do your research and make sure you don’t accidentally choose fish that won’t coexist well in your marine tank.

When you’re setting up your tank and considering who should inhabit it, you’ll need to be thinking about the following points. If you can’t answer these questions with your own research, it’s always best to seek expert advice!

Firstly, is this fish appropriate for life in a tank at all? Some species might seem like they can manage a life in an aquarium, but their actual requirements may prove too tricky for you to keep up with. If you’re comfortable with the size of tank that they need now, what about later on? Many varieties of marine life will require much bigger tanks as they grow.


Once the environment is right, it’s vital to figure out if your new fish will be bullied or harassed by the other inhabitants. Worse, it may become the bully and take over territory your other fish need. If you’re adding multiple types of fish to your new marine tank, it’s best to start with the least aggressive species first and add the most territorial occupants later. If you do this the other way round, the more docile fish won’t get any of the space they need as newcomers. Be especially careful with closely related species or reef fish with similar markings and colours, as this tends to lead to fiercer competition.

You might even realise too late that your fellow pets look more like food than friends to your new marine fish, so it’s vital to check their dietary preferences. Many marine tank occupants enjoy sampling all the food sources on offer, and will eat pretty much any invertebrate they come across. This makes them easy to feed, but completely unsuitable for reef tanks where they’re likely to eat the rest of their housemates.

Since there are so many factors to consider, there are plenty of tools around the Internet you can use to check the compatibility of the fish you’d like to occupy your tank. Once you’re confident about the size of marine tank you need, or if you still need some expert guidance, it’s time to contact us at Aquacadabra!