Flowerhorns are large aggressive cichlids, with that said they produce a lot of waste and often maul their tank mates. These fish need a decent amount of space to thrive and therefore shouldn’t be kept in small 10 and 20 gallon aquariums. A more suitable size aquarium is AT LEAST 60 gallons for a single flowerhorn, this sizing is recommended to provide adequate volume for proper dilution of waste products (less quickly changing water parameters), space to swim, grow and feel comfortable.
When waste builds up in a small aquarium the harmful substances found in the water can reach critical levels extremely fast. In a larger aquarium, there will be more leeway to perform a water change a day late or miss a tank cleaning without risking the death of your fish.
Space to Swim
Providing your Flowehorn with adequate space to swim and explore is just the right thing to do! I know, I’ve been to the pet stores too and see Flowerhorns in the tiniest cubicle (or partitioned) tanks no more than 10 gallons and they seem to be doing good. You might reason “my 15 or 20-gallon tank is larger than what the fish is living in now everything will be fine!” However, this isn’t the right thinking to have. When you bring a fish home, of course, its for your enjoyment but you want to set the fish up so it can thrive and live to meet its full potential. Always remember at the pet store they are living in those small quarters temporarily, hopefully until someone buys them and give them a proper home.
Flowerhorns are quite intelligent and tenacious fish some more than others. Watch quite a few different fish in my time some do better than others in small tanks. A handful of fish will bang the glass in their cubical as you check them out but others often run and hide behind the sponge filter in with them. No one wants skittish fish ( I absolutely can’t stand them) but providing your Flowerhorn with enough space to get away from attention when they need to can actually encourage your fish to start feeling more comfortable and start being brave.
So what size should tank should you keep your Flowerhorn in?
There are so many different opinions on this topic, but all experienced hobbyists agree on one thing that is to go for the largest aquarium that you can get. The bigger the tank and the more space you can provide your fish, the better. Benefits include a happy fish but also you will avoid having to size up later. When I started in the hobby I quickly when from 1 tank to 2 tanks to 3 tanks to 4 tanks within my year because I didn’t get the largest aquarium I could have the first time. Learn from me and everyone else who made the small tank mistake. All in all 60-gallon aquarium at the very least for 1 Flowerhorn specimen but get a 180 if you can it’s really not that much bigger 😉