How many tetras in a 150L tank?

[Bluebubbles]

Hi Guys,
I have a 150L tank with a tetra collection in it at the moment but I'm rubbish at maths and I don't know how to work out how many fish/tetras I can put in. So I can't help but worry that I've added too many. All fish are happy, healthy, and energetic and show no signs of stress or anything but it would be nice to finally put my worries to rest. And If someone knows an easy way to work this out too I would really appreciate it.

Thanks in advance,
BlueBubbles

 

[Colin_T]

What are the tank dimensions (length x width x height)?
What fish do you have in the tank?
How long has the tank been set up for?
How often do you do water changes and how much do you change?
Do you gravel clean the substrate when you do a water change?
How often and how do you clean the filter?
Do you have any plants in the tank?
How often do you feed the fish and what do you feed them?
Can you post a picture of the tank?

 

[Bluebubbles]

Thank you for your time,
I hope this covers all of your questions:
Not sure about the dimensions as I'm not home to measure.
I have a female betta, a few snails, a silver dollar fish, and my tetras. Not sure how many there are.
It's been set up for close to a year now.
I do a 75% water change every month.
I do not gravel clean unless there is a need for it.
There are two filters in this tank I change them alternating every two weeks so there is always a filter with beneficial bacteria.
I clean the filters monthly by cleaning off any algae and changing the media.
The media inside is a large sponge (to deal with large debris), a smaller sponge (for the smaller particles) and finally activated carbon charcoal (for the bioload).
There are many plants in this tank including driftwood with a plant growing off it.
All plants are live. This is why I don't gravel clean unless I need to it needs it.
I feed them tropical fish flakes at least every second day. I supervise them eating to make sure they are all the food is eaten.
I usually add a little bit at a time to make sure nothing is wasted.
I have attached some photos for you.

Please let me know if you believe I am doing anything wrong.
I am happy to look further into whatever I need too in order to make sure my bubbly family is not only having all of their needs met but also thriving.

Thanks again Colin_T for your reply. I hope you can answer my question.

 

[Barry Tetra]

Betta should not be kept with other fishes as they will kill/be killed (depending on how many tetras in the tank, and yes, my betta got bitten in a tail to almost death by tetras and guppies)
You can move the betta to tank atleast 3-5 gallons tank - the bigger, the better.

 

[Byron]

Aside from the purely biological issue of fish mass/water volume and maintenance factors...the species of the fish is equally important. Some fish are shoaling, which means there must be a group, and while we often have to suggest minimum numbers the fish will be healthier with more of their species. So for example, setting aside the issue of tank size, a group of 9-12 neon tetras will always be less stressed and thus healthier than a group of six.

Another important factor is the behaviour needs/traits of the species. Active fish should not be housed with sedate fish. Mildly aggressive fish might be impossible to keep with certain other species.

The water parameters matter, which includes GH, pH and temperature. Fish requiring cooler water--such as your neon tetras--will not be good tankmates for fish requiring warmer water, say the common or blue ram as one obvious example.

Water flow is another consideration; fish that prefer quiet still waters will have issues with a strong filter current, and given that this is 24/7 the fish cannot manage well.

Now to comment on a couple issues I see here, aside from new additions.

Partial water changes should be once every week, and somewhere in the 50-70% range. I know Colin will say much the same when he gets back. Many misunderstand water chemistry and water changes; there is no guide to tell when, it is a basic necessity for healthy fish. Filters cannot remove what we remove with water changes.

Silver Dollar fish are shoaling, and there should be six (or more), but this is a largish fish and they will eat plants, and they can get nasty to small fish. Re-homing the lone Silver Dollar would be advisable. This tank is not sufficient space for a group of them regardless of the other fish. And given the nice aquascape and the other fish, it would be a shame to ruin things with the wrong fish.

 

[Colin_T]

It's better for the fish if you can do a water change more frequently. I normally recommend a 75% water change and gravel clean the substrate once a week. If water is limited then a water change every 2 weeks is better than once a month.
Make sure any new water is free of chlorine/ chloramine before it's added to the tank.

Try to gravel clean any open sections of the gravel whenever you do a water change. You don't have to gravel clean the substrate where the plants are. Just come out a couple of inches from the base of the plants and work around them

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Beneficial filter bacteria takes about 4-6 weeks to established. If you are replacing filter pads every 2 weeks, you will be removing the beneficial bacteria and messing up the filter cycle.

Filter pads/ cartridges/ materials should only be replaced when they start to fall apart. If you have pads/ cartridges then add some sponge to the filter and leave it to run with the pad for a couple of months. Then chuck the pad and leave the sponge in the filter. Sponges last for 10+ years.

Sponges and other filter media get cleaned by squeezing or washing in a bucket of tank water and the media is re-used. The bucket of dirty water is poured on the garden/ lawn.

Carbon isn't necessary in an aquarium unless you have heavy metals or chemicals in the tap water. Then you should filter the tap water through carbon before adding it to the tank.

You can replace the carbon with another sponge for more filtration.

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Fish should get a varied diet and not fed on one type of food. You can buy various fish foods form pet shops or make/ grow your own. You can use raw/ cooked prawn, fish, squid and cut them into little bits and offer a few pieces at a time.

If you have aphids on roses in the garden, you can tap them into a bucket and offer them to the fish. Small ants, ant eggs and small termites are eaten by most fish, as are flies and mozzies caught without bug sprays.

If you have a bucket of water outside in the garden you might get mozzie larvae in it. These can be scooped out with a net, rinsed under tap water and fed to the fish.

You can buy Daphnia from some pet shops and culture them in a large plastic storage container containing green water. You can also collect Daphnia form freshwater ponds in the southern half of the country during autumn, winter and spring.

You can buy live brineshrimp from most pet shops and feed them to the fish.

The following link has information on culturing live foods for baby fish. It explains how to make green water and culture Daphnia if you're interested.

Back to Basics when Breeding Fish

STARTING OUT Make sure you have a pair, (1 male + 1 female). There is nothing worse than spending your hard-earned dollars buying a couple of fish to try and breed and ending up with a pair of fish of the same sex. Let's face it, to reproduce fish you need a male and a female. Two males won't do...

www.fishforums.net

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I would get rid of the silver dollars and possibly the Congo tetras, and then increase the number of other fish (black neon tetras, red phantom and rummynose tetras) so you have groups of 10 or so of each species of tetra.

However, if you have severe water restrictions and can only do a water change once a month, then get rid of the silver dollars and Congo tetras and maybe get 6 more black neons and rummynose.

 

[Bluebubbles]

Betta should not be kept with other fishes as they will kill/be killed

This is a very common misconception.
Thank you for your concern but she does great as well as the other fish that live with her.[/QUOTE]

 

[Bluebubbles]

I would get rid of the silver dollars and possibly the Congo tetras, and then increase the number of other fish (black neon tetras, red phantom and rummynose tetras) so you have groups of 10 or so of each species of tetra.

The silver dollar and larger tetras such as the congo are only there temporarily. I'm holding them for a friend as her tank started leaking. She has gotten a new tank but it's only about halfway through cycling so they'll be with me for another 3-4 weeks. I am also able to swap my fish over at my local fish store when they get too big.

Sorry, I should have mentioned this before. I didn't realise it would gain so much attention.

 

[Retired Viking]

The thing with Betta is that they are a type A personality fish. So even if he does not attack any other fish he is stressed when ever another fish comes into his territory or swims too close to him. They are bread that way. That is why they are known as fighting fish and do not even get along with their own kind even the females and can attack and even kill them. The stress alone will shorten his life. I wish you good luck and hope it works out for you but I would suggest keeping him in his own tank with a snail or two.

 

[Retired Viking]

On you tetra question I have a 55 gallon tank with shoals of neon, glow light, ember tetras and 1 red eyed tetra around 35 fish and still have room. It depends on the size of the tetra you want. I like the smaller ones. The neon and glow light like to hang together while the ember like to hang in my anacharis "forest" on one side of the tank.

 

[Bluebubbles]

Betta should not be kept with other fishes as they will kill/be killed

I do my research before I buy them.
My tank sits at about 25 which is fine for a neon tetra as they are to be kept in water 21-27 degrees.

 

[Bluebubbles]

On you tetra question I have a 55 gallon tank with shoals of neon, glow light, ember tetras and 1 red eyed tetra around 35 fish and still have room. It depends on the size of the tetra you want. I like the smaller ones. The neon and glow light like to hang together while the ember like to hang in my anacharis "forest" on one side of the tank.

Thank you. This has been the most helpful answer to my question.

 

[Bluebubbles]

Partial water changes should be once every week, and somewhere in the 50-70% range.

I only do it every month because this is when the nitrate begins to move toward 10.
I don't let it pass 10 if I can help it.

 

[Retired Viking]

150liter sounds good for neon tetra, I have had very good luck with the glow light tetras, I have not lost one yet and they are good looking and hang well with the neon tetra. You should have at least 6 of each type of tetra, I try for 12-15. Neon have had health problems lately so I have not bought any for some months now. I really like their color but inbreeding has hurt them. I hope to find some wild neon tetra to replace the ones I lost. I do a 40-50% water change every week and use RO water to soften my hard water.

 

[Bluebubbles]

Make sure any new water is free of chlorine/ chloramine before it's added to the tank.

Of course, I treat the water before its added to the tank with a stress coat which also removes chlorine, etc. I also heat it before adding it with my spare aquarium heater so there are no traces of metal from using hot water and so I don't stress out the fish with cold water.