How many fish for my 130L community?

[Keenamoss]

Hi there - I'm a beginner, am setting up a 130L planted tank atm. I have my heart set on one male betta, a bristlenose plec, and 6ish (?) harlequin rasboras.. I really really would LOVE a little crew of albino corydoras as well - would rather have them than the pleco but helping out a friend - could I have them all, or is this too many beings in a tank? Also, would 6 harlequins be enough? Thanks for your thoughts.

 

[ClownLurch]

Welcome.
You’ll be told by dozens on here that Bettas aren’t community fish. They’re right. They don’t want fish deaths on their consciences. Neither do you. Trust me.
Also to find out your water parameters ie hardness and ph. Do it ASAP it’s the most important thing you need to know. It’ll be on your water providers website. They’ll need figures not words. Enjoy it here it’s great. They know just about everything you’ll need to know.

 

[Keenamoss]

Welcome.
You’ll be told by dozens on here that Bettas aren’t community fish. They’re right. They don’t want fish deaths on their consciences. Neither do you. Trust me.
Also to find out your water parameters ie hardness and ph. Do it ASAP it’s the most important thing you need to know. It’ll be on your water providers website. They’ll need figures not words. Enjoy it here it’s great. They know just about everything you’ll need to know.

Thanks! So excited.
Hmm other resources have full lists of super compatible tank buddies for betta fish, but it can depend on the individual's personality? The local pet shops do free water testing so I'm taking a bit of water down there once a week or so to have it checked out, before getting a testing kit for home. Didn't think about contacting the water provider tho! Golden, thanks.

 

[Essjay]

I agree with ClownLurch. bettas are solitary fish. A lot of websites do say they can be kept with other fish but we have seen on here how a betta is seemingly fine with other fish then suddenly snaps and goes on a killing spree.

Bryon explains things very well

Betta splendens seems to live solitary in its natural habitat which is still and sluggish waters, including rice paddies, swamps, roadside ditches, streams and ponds. Such an environment is not conducive to fish that require oxygenated waters so one can expect few if any non-anabantid species to live in such habitats. During the dry season, most Bettas are able to bury themselves in the bottom of their dried up habitat. There, they can live in moist cavities until water once again fills the depression during a rainy period. The fish can survive even if thick, clay mud is all that is left of the water. They do not survive total drying out of the bottom. (Vierke 1988) There are very few fish species, and none that are found in the same habitats, that can manage life in such conditions, which is further evidence that the B. splendens is most likely a solitary species.

All anabantids are territorial; male bettas instinctively fight each other in defending their territory. Selective breeding over many years has produced fish with a heightened sense of territory defense, which explains the common name of Siamese Fighting Fish. Fish fights for money is a "sport," if you want to use the term for such animal cruelty. This means the Bettas we see in stores have an even greater propensity to literally kill each other given the chance. For a fish that instinctively lives alone, and believes it must defend its territory to survive--both traits that are programmed into the species' DNA--this aggressiveness is likely to extend to any fish that dares enter the Betta's territory, which in most cases will be the tank space. And forcing the fish to "live" under such conditions is frankly cruel and inhumane.

Individual fish within a species do not always adhere to the "norm" for the species; this is true of all animals, including humans. But with fish, responsible aquarists should research the fish's behaviours, traits, and requirements, and then aim to provide accordingly. "Expectations" are as I said above programmed into the DNA, and we are not going to change them just because we may want to have a Betta in the tank with "x" fish species. Sometimes the Betta seems to co-operate with our experiment, but in the majority of cases it will not, eventually if not immediately. Fish that do succumb are likely being severely stressed, unseen to the aquarist until it is too late.

If the Betta does not first attack the intruders, the intruders may go after the Betta. It is a two-way street, and in either situation it is the Betta that loses in the end. Severe stress causing increased aggression, or conversely severe withdrawal from being targeted by the other fish. And physical aggression is not the only concern; fish release pheromones and allomones, chemical communication signals that other fish read, and these can promote aggression that will in time weaken the fish to the point of death.

The water suppier's website is the first place to look for hardness - and we need the unit of measurement as well as the number as there are about half dozen different units they could use.

The reason we ask for hardness is because fish that originate in hard water do not do well in soft water, and soft water fish do not do well in hard water. We should try to keep fish which come from water with similar hardness to out tap water.

 

[Keenamoss]

I feel like we are learning all the time and there's always more to learn
Aside from the betta debate, imagining another pretty and single, upper level fish if need be, do you guys think that the tank is big enough for that kind of set up? Is 6 harlequins enough for them to relax and do their thing? Would adding 5 corydoras be way too much or maybe OK, or not a big enough school size for the corys to really want to bother? Thanks for your thoughts

 

[AdoraBelle Dearheart]

I feel like we are learning all the time and there's always more to learn
Aside from the betta debate, imagining another pretty and single, upper level fish if need be, do you guys think that the tank is big enough for that kind of set up? Is 6 harlequins enough for them to relax and do their thing? Would adding 5 corydoras be way too much or maybe OK, or not a big enough school size for the corys to really want to bother? Thanks for your thoughts

People aren't really going to be able to answer those questions without knowing things like your water hardness.

6 harlequins would usually be fine for a 34 gallon/130 litre, but a few more is always better. But if your water is too hard for them, the question becomes academic and you need to rethink the plan anyway.

Corydora, again, depends on your water hardness, and which species you want. A few different species have albino colour varieties, and whether your tank could handle six of them depends on what species you get, which depends on your hardness and what species are available to you/affordable, and what other tankmates you chose, etc. So you could go out and buy six albino schwartzi cories which get pretty big, then find that your water is too soft for them and they outgrow your tank, when you could have had nine or 12 corydoras sterbai. Or get sterbai, but then find that those need harder water than the rasboras, and on and on it goes. Best to pin down your water parameters first, then look at what options appeal to you, and people can let you know what species could work in your size tank, in your water, and with the other fish species you want.

 

[Keenamoss]

People aren't really going to be able to answer those questions without knowing things like your water hardness.

6 harlequins would usually be fine for a 34 gallon/130 litre, but a few more is always better. But if your water is too hard for them, the question becomes academic and you need to rethink the plan anyway.

Corydora, again, depends on your water hardness, and which species you want. A few different species have albino colour varieties, and whether your tank could handle six of them depends on what species you get, which depends on your hardness and what species are available to you/affordable, and what other tankmates you chose, etc. So you could go out and buy six albino schwartzi cories which get pretty big, then find that your water is too soft for them and they outgrow your tank, when you could have had nine or 12 corydoras sterbai. Or get sterbai, but then find that those need harder water than the rasboras, and on and on it goes. Best to pin down your water parameters first, then look at what options appeal to you, and people can let you know what species could work in your size tank, in your water, and with the other fish species you want.

Thanks for this I guess I was taking that for granted, my main question pertains to space for the health and happiness of the fish, as I'm just going through my options from species I like that have similar requirements in temperature, pH and gh, but do you reckon that will cover it? How important are things like water flow/environmental differences in natural habitat etc? Thanks

 

[AdoraBelle Dearheart]

Thanks for this I guess I was taking that for granted, my main question pertains to space for the health and happiness of the fish, as I'm just going through my options from species I like that have similar requirements in temperature, pH and gh, but do you reckon that will cover it? How important are things like water flow/environmental differences in natural habitat etc? Thanks

If we assume that all the species you pick will work in your water (which we can't, but for the hypothetical here) what do you mean will that cover it?

Space is one aspect, but if you have a large pleco in there, not only will that limit how many other bottom dwellers you can add, but since plecos are a messy fish and produce a lot of waste, that has a knock on effect to how many other fish you should get, like a smaller school of rasbora since the bioload of a pleco plus a large school of rasbora might be too much.

How important water flow is depends on a lot of factors too. How much filtration there is (how many litres per hour, filter media etc) is important and varies depending on species/plant load/how stocked your tank is, How much flow there is in the tank is important too. If you got hillstream loaches, they need a lot of flow and highly oxygenated water, since that's what they've evolved to live in. But a betta fish can't tolerate a lot of flow; they just weren't 'designed' to live in water that is buffeting them, and large fins create a lot of drag and damage easily, leading to much higher potential for stress and infections.

How important are differences in natural habitat is a worrying question. I think when we're choosing to keep a fish in captivity, we're caring for living beings, not ornaments. Providing the most natural environment we can is going to be the best possible environment for the fish. They have no choice and no escape, and if we make a mistake and keep them in the wrong size tank, the wrong water or with the wrong species, the price is death. High stress leads to death, high stress means an unhappy fish that isn't thriving, and increases their vulnerability to disease. For many species, certain elements of their natural habitat are crucial, while others have a more varied range and are less specialised.

If you're butting up against the idea of one tank with different species that require very different habitats, then I'd suggest turning back from that idea now. Trying to maintain a middle ground so that neither set of fish is getting what they need doesn't usually mean they'll meet happily in the middle, it usually means more stressed fish.

When you're new to the hobby, there's a very steep learning curve. It's better to take your time and research, then research some more, and then a bit more to be on the safe side. If you don't know why a fish keeping 'rule' is in place, then investigate why before deciding to ignore it. If you're choosing to ignore things like water hardness or the fact that bettas are a solitary species, or adding way more stock than your tank can handle, then the hobby becomes less enjoyable when your fish start to suffer illnesses and die. At least learn what the rules are and why they're repeated so often before trying to push their boundaries.

 

[Essjay]

Water flow is important. Generally speaking there are sedate fish which swim slowly around a tank and fast swimmers which dash around a tank. Sedate swimmers need a slow water flow while fast swimmers tend to prefer a faster flow.
For example, all the fish in your first post are sedate swimmers and need a slow water flow.

We should try to replicate to some extent the environment that fish originally come from. For example, those fish from rocky, plantless rivers or lakes should have a lot of rock; those that come from densely planted waters need somewhere for the fish to hide in. Fish that like to spawn in caves should have caves provided but as long as there is a cave like structure they don't mind what it is made of. If bottom dwellers are intended, sand is better than gravel. White substrates should be avoided as no fish have evolved over white.

 

[Keenamoss]

Water flow is important. Generally speaking there are sedate fish which swim slowly around a tank and fast swimmers which dash around a tank. Sedate swimmers need a slow water flow while fast swimmers tend to prefer a faster flow.
For example, all the fish in your first post are sedate swimmers and need a slow water flow.

We should try to replicate to some extent the environment that fish originally come from. For example, those fish from rocky, plantless rivers or lakes should have a lot of rock; those that come from densely planted waters need somewhere for the fish to hide in. Fish that like to spawn in caves should have caves provided but as long as there is a cave like structure they don't mind what it is made of. If bottom dwellers are intended, sand is better than gravel. White substrates should be avoided as no fish have evolved over white.

Thanks I understand about mimicking the fish's natural environment as best we can, that prompted me to go for planted with lots of nooks and crannies and resting spots because originally it was just to keep a betta. Further research suggests the other types of fish I mentioned enjoy similar things, but I was mainly wondering if in your experience a bristlenose can be happy just with a controlled filter flow? (Assuming all else is well, filter the right size working properly and plenty of plants, driftwood and caves and appropriate water parameters and the correct food and time for foraging in the darkness and regular love and maintenance etc ) as thats the main *environmental* issue I've wondered about because they live in streams and things naturally and if, hypothetically a betta could happily share a planted 130l tank with a pleco, it would be under conditions where the flow isn't throwing him around the place all day. The filter has a mechanism to reduce the flow but have also thought about making a diffuser type thing for the output as it still seems quite strong, for the betta's comfort. Providing their oxygen and poop requirements are met, wondering if this would still stress the pleco because they just want more water movement over them?

Also I put sort of a fine black gravel, lots of tiny chunks, when I thought I was only going to have a betta, into the tank when I bought it. Would this be too rough for pleco and/or corys in your experience? I see corys shuffling around sand and they look sooo cute and happy, and others on gravel that sort of seem to go round touching the surface of it without digging - would a sanded area, laid on top of gravel be enough to provide them with that enrichment or are they likely to still try to dig down and hurt themselves, so would need to totally sand up before having them? Thanks again

 

[Essjay]

Depending where you look, bristlenoses come from fast flowing water (planetcatfish) but Seriously Fish comments that its precise origin is unknown with some people believing commercially bred bristlenoses are hybrids. But this is a fish which seems to do well in all types of tank with many different species. As long as there's a cave and some wood in the tank, water flow doesn't seem to make a difference.

The black gravel, if you rub some between your fingers does it feel rough or sharp?
Cories feed by taking a mouthful of substrate and sifting it for food then passing the substrate out through their gills. They can't do this if the particles are too large. Sharp particles erode their barbels; damaged barbels allows bacteria to get in and cause an infection. Uneaten food etc gets down into gravel and rots forming a breeding ground for bacteria.

However ..... bettas are not community fish. Despite what you may read on other sites, it is never a good idea to keep bettas with other fish. A betta may live peacefully for several months, then he snaps and goes on a killing spree. Or the other fish may pick on him. Even the most placid fish often can't help themselves when faces with long flowing fins. And there is chemical aggression as well as physical. Fish excrete pheromones and allomones to communicate with each other. We can't see these or measure them but fish will detect 'aggression' hormones in the water and it will cause them stress.
Bettas should be kept alone.

 

[Keenamoss]

Depending where you look, bristlenoses come from fast flowing water (planetcatfish) but Seriously Fish comments that its precise origin is unknown with some people believing commercially bred bristlenoses are hybrids. But this is a fish which seems to do well in all types of tank with many different species. As long as there's a cave and some wood in the tank, water flow doesn't seem to make a difference.

The black gravel, if you rub some between your fingers does it feel rough or sharp?
Cories feed by taking a mouthful of substrate and sifting it for food then passing the substrate out through their gills. They can't do this if the particles are too large. Sharp particles erode their barbels; damaged barbels allows bacteria to get in and cause an infection. Uneaten food etc gets down into gravel and rots forming a breeding ground for bacteria.

However ..... bettas are not community fish. Despite what you may read on other sites, it is never a good idea to keep bettas with other fish. A betta may live peacefully for several months, then he snaps and goes on a killing spree. Or the other fish may pick on him. Even the most placid fish often can't help themselves when faces with long flowing fins. And there is chemical aggression as well as physical. Fish excrete pheromones and allomones to communicate with each other. We can't see these or measure them but fish will detect 'aggression' hormones in the water and it will cause them stress.
Bettas should be kept alone.

Thanks good to know waterflow wouldn't be the issue re pleco. The black gravel doesn't feel "sharp" exactly, just sort of rough, like um gravel lol some of it is quite dusty tho, very fine, and I'm thinking it would probably be OK but now I'm a little concerned that corys prefer slightly cooler water than bettas anyways so.. just giving that some extra thought. I am now also wondering about tannins! But that's another thread

I appreciate the message again re betta being "fighters" though it really wasn't my question I know it comes from care and concern for these little beings we are responsible for as pet owners. And I'm aware everyone has different opinions and knowledge and experiences outside of this forum that they draw from, as it has been repeated I will just share my rationale for this idea just so you know that I am actually thinking on it, and I wouldn't take any action with any living being just on a whim. I guess I didnt think of having to explain myself in so much detail, I forgot what forums are like!

Its just that my understanding is that wild betta live in diverse, if tiny, communities in nature- males will often get super aggressive when defending their babies or territory against other males, that is true... and they were intentionally bred for fighting for a fair few decade's that is true; and there are plenty of stories where a betta mum or dad tried to introduce tank mates and it didn't work out, and it was very apparent very quickly, and there was a handy Plan B tank ready to go.

Very often though, when the space is large enough, when no body is stressed, and there are plenty of plants and hideyholes, a male betta will thrive in a tank with certain species of other fish without violence- smaller fish, who aren't too bright or long finned, and who prefer to occupy a lower or middle area of water, and who are faster swimmers (maybe that is a Just In Case proviso?)- including all the ones I mentioned earlier, and this set up actually mimics the bettas natural habitat.

While they can survive the sort of cramped solitary lives people tend to give them, they don't actually live like that in the wild.. true, they don't swim great distances, but they are never confined to "puddles" for long, as petshops and things will have you believe. Just google Thailand marshes, even the tiny underwater worlds of rice paddies- that's where betta will be, amongst many other bottom dwellers and midrange swimmers. So it just doesn't make sense to me to keep him on his own, unless of course he is a very aggressive individual, which will be apparent very quickly and for which there is a Plan B.

Almost all fish who are big enough have the potential to go on a nipping/killing spree, from the looks of things - I keep reading horror stories about people waking up to massacres with all different types of species... surely there would be many different factors including feeding/space/triggering changes in the environment etc that could cause something like that even from within the same school.
Anyway that's where my head is at though I appreciate everyone's opinion, based on the evidence to me at this stage, I feel like it's worth a (careful) shot.

 

[Keenamoss]

*by 'careful', just to clarify, I mean ticking all the boxes: other fish in tank first so he's not immediately territorial, watching him in the bag during acclimatisation for how he responds to the other fish when they check him out, SUPERVISE and if signs of trouble or a lot of aggression, which for betta is a lot of flaring and flashing around well before anything else, and if so then quickly get him out of there and into your plan b tank before any one gets hurt. And you know. Regroup and reassess the situation lol.

 

[AdoraBelle Dearheart]

You don't have to explain yourself. At the end of the day, people can choose what to do with their own tanks, and there are plenty of people out there who will argue all day that they've kept bettas in communities successfully for years.

I do think that there is some inherent confirmation bias at play in cases like these though. I've yet to see anyone argue that bettas will be lonely and suffer if kept alone, and the arguments that are pro-bettas with other species are from people who want to keep a betta with others for their own benefit, not because bettas need a group or the group needs a betta. It's much easier to accept 'evidence' if it confirms your own preferences.

Even pro-bettas in communities advice comes with a lot of caveats. "depends on the temperament of the fish" "have a back up plan" etc etc, which sets off alarm bells for me. Personally I've never had a betta and have no plans to, so I have no dog in this fight, if you'll excuse the turn of phrase.

I do have an interest in scientific research though, and when I looked into the debate, found it frustratingly difficult to find real research on the wild habitats of betta fish that wasn't tucked behind a paywall.

Its just that my understanding is that wild betta live in diverse, if tiny, communities in nature- males will often get super aggressive when defending their babies or territory against other males, that is true...

Where did you find evidence that betta live in diverse communities in the wild? I would love to read more about their natural habitat and other species that share the waters, if you don't mind sharing links. Most of what I know comes from @Byron . I trust his information because I know he does real research based on as much scientific evidence as he can find. As Essay shared, he says;

"Betta splendens seems to live solitary in its natural habitat which is still and sluggish waters, including rice paddies, swamps, roadside ditches, streams and ponds. Such an environment is not conducive to fish that require oxygenated waters so one can expect few if any non-anabantid species to live in such habitats. During the dry season, most Bettas are able to bury themselves in the bottom of their dried up habitat. There, they can live in moist cavities until water once again fills the depression during a rainy period. The fish can survive even if thick, clay mud is all that is left of the water. They do not survive total drying out of the bottom. (Vierke 1988) There are very few fish species, and none that are found in the same habitats, that can manage life in such conditions, which is further evidence that the B. splendens is most likely a solitary species."

 

[Keenamoss]

It's 2am and my second consecutive late night of internet rabbithole fishiness lol but it is certainly my new obsession, though I haven't actually checked for anything peer reviewed, but let me get back to you? Maybe we can start a new thread and share resources and inspire maybe some new researchers if we find the empirical literature lacking re natural wild habitats.... In the meantime a basic Google search yields:

The Natural Habitat of Betta Fish

The betta splendens -- those colorful little living jewels found in teeny, tiny cups in pet stores -- are not, as the pet store chains would have you believe, found in mud puddles or watery footprints of oxen. They actually live in a large, biodiverse ecosystem in parts of Asia.

pets.thenest.com

Though of course not what you're asking for but. Will need a little more brain power for that