How many fish in a 28litre tank

[Kaylab2021]

Hi there i am new to owning fish and bought a 28litre tank for my betta fish i bought male and a bumblebee catfish. I thought the betta looked lonely and was always looking for my catfish so i decided to put 2 harlequins and 3 neon tetras in the tank. This has been running for over a month now. I noticed the other day my catfish looks like it has dropsy and is just staying at the top of the tank. I dont have a medical or spare tank so i have been adding aquarium salt to the hole tank hoping it might help. I also did a 50% water change and will be doing 20% water changes daily until sorted. I also ordered some ramshorn nails i only put 1 in the tank so far. Has my tank got to many fish in it? Any help will help a lot

 

[Bruce Leyland-Jones]

Hi.
I'll assume the dimensions are something like 41 x 38 x 26cm.

Different fish have different water requirements. Have you tested your water and do you know the hardness, ph, ammonia, nitrite and nitrate levels? If not, you need a test kit to give you this essential info.
Do you use a water conditioner when you do a water change?

When looking at what fish to place in a tank, normally it's good to match the fish to the water you're giving them to live in.
When you know what fish will thrive, you then start to look at the space you have in the tank.

In the olden times, before proper knowledge was more widespread, there used to be a 1" of fish per gallon rule. 48 litres equates to about 10 gallons, suggesting you could have a total of 10" of fish in the tank. Your tank is currently over-stocked.

Then, you have to take into account the individual needs of the fish.
To thrive and be happy, Neon Tetras need to be in a shoal of at least 8.
Harlequin also need to be in a shoal of at least 6.

I thought the betta looked lonely and was always looking for my catfish

Fish do not have human emotions and your Betta would not be 'lonely'. His looking for the catfish would be more likely to chase it away. Betta males can be very territorial and most of us would agree that putting any other fish in with a Betta male is just asking for trouble. The internet is full of people saying how their Betta is perfectly happy, with lots of other fish, but essentially, Betta ARE territorial and when the mood takes them, they can be very, very punchy.

Your Bumblebee catfish needs meaty foods and would eat anything small enough to swallow. (These grow to about 6"). They can also be territorial. These are shy fish and any exposure will stress them out. They are mainly nocturnal in habit.

 

[Essjay]

I'm afraid it is very overstocked. A 28 litre tank is suitable for just the betta I'm afraid. The only other fish suitable for this size tank are small enough to risk the betta seeing them as food.

Harlequins and neon tetras need a tank at least 60 cm long and a shoal of at least 6, preferably more, of each one.
Bumblebee catfish seems to be a name used for several different fish, but the one that crops up most often is a 15 cm fish which needs a 120 cm tank.

 

[Bruce Leyland-Jones]

Please check this out, to learn about the needs of different fish.
It's far from perfect, but is an excellent starting point.

 

[Kaylab2021]

Hi there

Hi.
I'll assume the dimensions are something like 41 x 38 x 26cm.

Different fish have different water requirements. Have you tested your water and do you know the hardness, ph, ammonia, nitrite and nitrate levels? If not, you need a test kit to give you this essential info.
Do you use a water conditioner when you do a water change?

When looking at what fish to place in a tank, normally it's good to match the fish to the water you're giving them to live in.
When you know what fish will thrive, you then start to look at the space you have in the tank.

In the olden times, before proper knowledge was more widespread, there used to be a 1" of fish per gallon rule. 48 litres equates to about 10 gallons, suggesting you could have a total of 10" of fish in the tank. Your tank is currently over-stocked.

Then, you have to take into account the individual needs of the fish.
To thrive and be happy, Neon Tetras need to be in a shoal of at least 8.
Harlequin also need to be in a shoal of at least 6.

Fish do not have human emotions and your Betta would not be 'lonely'. His looking for the catfish would be more likely to chase it away. Betta males can be very territorial and most of us would agree that putting any other fish in with a Betta male is just asking for trouble. The internet is full of people saying how their Betta is perfectly happy, with lots of other fish, but essentially, Betta ARE territorial and when the mood takes them, they can be very, very punchy.

Your Bumblebee catfish needs meaty foods and would eat anything small enough to swallow. (These grow to about 6"). They can also be territorial. These are shy fish and any exposure will stress them out. They are mainly nocturnal in habit.

The dimensions are correct

Hi.
I'll assume the dimensions are something like 41 x 38 x 26cm.

Different fish have different water requirements. Have you tested your water and do you know the hardness, ph, ammonia, nitrite and nitrate levels? If not, you need a test kit to give you this essential info.
Do you use a water conditioner when you do a water change?

When looking at what fish to place in a tank, normally it's good to match the fish to the water you're giving them to live in.
When you know what fish will thrive, you then start to look at the space you have in the tank.

In the olden times, before proper knowledge was more widespread, there used to be a 1" of fish per gallon rule. 48 litres equates to about 10 gallons, suggesting you could have a total of 10" of fish in the tank. Your tank is currently over-stocked.

Then, you have to take into account the individual needs of the fish.
To thrive and be happy, Neon Tetras need to be in a shoal of at least 8.
Harlequin also need to be in a shoal of at least 6.

Fish do not have human emotions and your Betta would not be 'lonely'. His looking for the catfish would be more likely to chase it away. Betta males can be very territorial and most of us would agree that putting any other fish in with a Betta male is just asking for trouble. The internet is full of people saying how their Betta is perfectly happy, with lots of other fish, but essentially, Betta ARE territorial and when the mood takes them, they can be very, very punchy.

Your Bumblebee catfish needs meaty foods and would eat anything small enough to swallow. (These grow to about 6"). They can also be territorial. These are shy fish and any exposure will stress them out. They are mainly nocturnal in habit.

Hi there dimensions are correct i do add water coat and stress coat every water change. The water test kit i bought was cheap and i do not think it reads properly. I do need to buy a new one. If the catfish has got dropsy will it die

 

[Animallover😍]

I'll assume the dimensions are something like 41 x 38 x 26cm.

In the olden times, before proper knowledge was more widespread, there used to be a 1" of fish per gallon rule. 48 litres equates to about 10 gallons, suggesting you could have a total of 10" of fish in the tank.

The OP said the tank was 28 litres, but the dimensions say otherwise...

 

[Animallover😍]

If the catfish has got dropsy will it die

Usually they do. If it does it's best to euthanize.

 

[Bruce Leyland-Jones]

Hi there dimensions are correct i do add water coat and stress coat every water change. The water test kit i bought was cheap and i do not think it reads properly. I do need to buy a new one.

Stress coat simply adds aloe vera to try and supplement the protective mucous coat of a fish. This will not dechlorinate your tapwater.
I don't know what you mean by 'water coat'.

How do you know that your test kit is inaccurate?

If the catfish has got dropsy will it die

IF the catfish has dropsy, it will probably die. You don't know what's wrong yet.

 

[Bruce Leyland-Jones]

The OP said the tank was 28 litres, but the dimensions say otherwise...

Put '28 litre tank' into Google...

 

[Kaylab2021]

Im guessing it has dropsy from reading google he has a small bloated belly sits at top of tank and some times seems to lay on its side at the top of the tank. As for the water test strip it seems to read the same readings each time even when put under tap. And i use a water dechorinater for safe tap water.

 

[Kaylab2021]

So i now know my tank is over populated, i dont have a spare tank and i dont no anyone with a tank to adopt some of my fish. For now if i do daily water changes will the fish be ok? They all seem happy and are swimming and eating fine obviously apart from the catfish

 

[Byron]

So i now know my tank is over populated, i dont have a spare tank and i dont no anyone with a tank to adopt some of my fish. For now if i do daily water changes will the fish be ok? They all seem happy and are swimming and eating fine obviously apart from the catfish

Can you return the neon tetra and rasbora to the store perhaps? This woold be the best option. The catfish, I won't guess as to possible disease issues, but the store is unlikely to take back a possibly sick fish.

There is more to this than just the numbers in the small tank. Tetras and rasboras are shoaling fish, and they must be kept in a group of their own species. Everyone always want minimum numbers, but the fact is that the more there are of the species the better (= healthier) the fish will be. Ten is about minimum for any of these fish. Obviously there is not sufficient room for this many, hence the suggestion to somehow remove them.

As for the problem with too few of a species, it has a few aspects. First, studies have now proven without question that fewer than ten will almost always cause increased aggressive behaviour in all characin species. Even normally peaceful fish can have nasty interactions among their own species and beyond. This does not bode well either for the tetras or the Betta who is likely to become a target. Another aspect of numbers within the species is more involved, but the same study indicated that in larger groups the fish actually ate better, so they were obviously healthier. By this I do not mean they ate better food, but their "attitude" to feeding was improved. Hard for me to put into words, but it is a clear sign of another benefit of the group size.