Tropical Fish Tanks Fish Tank Guides

The Community Tank


A few thoughts to consider before starting a community aquarium

Starting a community

When starting your first aquarium it seems pretty frequent that people opt for a community type tank.  This is what I did on my first ever aquarium and I have done others since.  Many think that a community aquarium is the easiest to care for and will be easier to maintain, but that isn’t necessarily the case. Community aquarium maintenance is exactly the same as any other aquarium really, and choosing your fish can be just as tricky as there are so many types of community tank.

This is because there are so many ‘community fish’ to choose from, but being community fish doesn’t mean that they will all get along.  Today I’m going to talk about a few things to check before you start your community tank.


Some things to check before you put fish into an aquarium together are:

Do they come from water with the same parameters?

Do they eat the same food?

Are they schooling fish?


Water parameters

Water parameters are very important for fish. If two fish do not come from the same water conditions then they should not live together.  Two commonly differing factors are pH and water hardness.  A good example of two types of fish that are frequently kept together and come from different pH water is African and American Cichlids.  Whilst these are not your standard community fish, this still equates to a form of a community tank.

African lake Cichlids prefer a higher pH, most advice says between 7.8 and 8.5, but the water they actually come from is between 8 and 9.  American Cichlids come from water of lower pH, 7.8 or below for Central American and lower still for South American.  Whilst this seems like a small difference and based on some advice only just overlaps, it is still different.  Incorrect pH can lead to death in fish, so with a mix of any 2 of these species in the same aquarium, at least 1 has to be outside its ideal requirements, so is likely to be stressed.

This is something I’ve seen happening fairly regularly and many people will argue that farm-bred fish do not require the same pH as they would have come from in the wild.  This seems like a myth to me as I cannot see how a few generations of farm breeding can undo millions of years of evolution.

Water hardness is important too, the effects are similar to pH if a fish is kept in water that is outside of its optimal conditions.  Guppies come from hard water but I often see them kept with the likes of beta fish.  Betta like soft water, so again in this community, at least 1 species is living outside its optimal water conditions and cannot thrive.

Another factor to think of with water parameters is temperature. Temperature is vital as different temperatures will affect your fishes metabolism and in turn affect its lifespan.  Higher temperatures increase fish metabolisms which then decreases its lifespan.  So, if you put a Goldfish (cold water) in a tropical (warm water) aquarium, it will grow very fast but will not live as long as it may have done in a cold water environment. (Note: please don’t try this as there are more factors other than temperature that mean it really doesn’t work.)

You can learn more about testing your water here.

water test kit API master


Always consider feeding when starting your community tank.

Food is really important to fish, clearly, they need it to survive, but they need the right type of food to remain healthy.  Some fish require more meaty foods, some require more vegetable matter.  A fish that primarily feeds in the wild on vegetation can suffer from bloat if fed too many meaty foods.  A fish that requires more meaty food may not get all the protein that it needs to grow from a veggie-based food.

It is possible to add more than one type of food to the aquarium to cater to both, but fish won’t sit down at a table and only eat what they are supposed to.  So whilst it is possible to keep the two together, keep an eye on what they’re eating.

Another factor to consider with food is that some fish will out-compete others to get to the food first.  A good example of this is Tiger Barbs. These guys can nip fins so not the greatest community fish around, but they are a good example of a fast, greedy fish that will hoover food up before slower swimming or nervous fish have a chance.

fish food flakes

Schooling fish

Schooling fish like to live in groups, so a factor to consider here is ‘Do you have enough space for them?’.  Many schooling fish are recommended to be kept in groups of 6 or more, realistically though this number should be higher.  How often do you see a school of 6 fish in the wild?  A better number, in my opinion, is 20, but the more fish there are the happier the fish will be.  Schooling fish have adapted over millions of years to survive by ‘safety in numbers’, so if you only have a few they can become nervous, then stressed, then deceased.

Neon Tetra are a good example of this, I often see small aquariums housing a couple of neons, they are popular, pretty little fish, but they are often hiding around decor in these situations.  This is the nervousness/stress of being in a small group.  A school of 20 in a larger aquarium looks amazing!


So there are a couple of things to think about when it comes to starting a community tank.  I always recommend a spot of research before buying a new fish to ensure they are compatible, this will save you many issues further down the line.


Have fun building your first community tank and as always, hit the comments below!

About the author

James @Seriously Fishy

I am a fish keeping enthusiast with over 20 years experience. I currently keep American Cichlids (CA) which are my favourite fish to keep so far. I started Seriously Fishy as I noticed a large volume of people on various web pages looking for help with Aquarium basics. I created the first Seriously Fishy book to solve the issue in 28 pages, that led to the Seriously Fishy UK fish forum and blog.

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