Let's Have A Debate On Betta Tank Size.

[Chad]

...survived fine...

I'll say it first because someone is going to...we want our fish to thrive...not just survive.

 

[eaglesaquarium]

 

...survived fine...

I'll say it first because someone is going to...we want our fish to thrive...not just survive.

 
I don't disagree with the sentiment, but how do we define 'thrive'?   Survive is an easy one to define, and can objectively be measured easily, even by the most inexperienced of folks.  'Thrive' has a far less black and white set of parameters.  How do you objectively define it?

 

[Chad]

Fatness, activity, fin condition, scale condition, the ability to defend itself and/or compete for resources in the tank. I've seen yellow tangs that are surviving and when you compare them to one that is thriving it's easy to quantify the difference. 

 

[eaglesaquarium]

Fatness, activity, fin condition, scale condition, the ability to defend itself and/or compete for resources in the tank. I've seen yellow tangs that are surviving and when you compare them to one that is thriving it's easy to quantify the difference. 

 
I guess the question I have is where is the line specifically drawn between the two, certainly there is a gradient, but where is the optimum line between 'surviving but not thriving' and 'surviving and thriving enough' to get to the line of demarcation for minimum tank size?  (Or is this only about 'optimum'?  And then we have to have a line for where 'optimum' thriving takes place.)  I agree with Ch4 regarding the lack of a single answer, as the answer generally comes down to the actual husbandry than it does anything else.
 
For discussion, you have posited:
 

• Fatness (I assume you mean the girth of the animal), but there would be a range of 'acceptable' and too lean or too bloated would be negative.
•  
• Activity - how do you define activity that is sufficient before lethargy that would be considered detrimental starts?
•  
• Fin condition - this looks to be a very easy objective mark.  Ideally, we want perfect fins, which would be why one would be keeping bettas in the first place... the beautiful finnage.  So, for me, any tear would be below the goal for thriving.
•  
• Scale condition - again, this is easily objectified.  Any missing or discolored scales would be below the ideal standard.
•  
• ability to defend itself?  Not sure on this one.  What would a lone betta need to defend itself from?
•  
• competition for resources - a lone male betta would have no competition for resources, would it?  
•  

 
If we consider the last two, then a larger issue comes up besides just tank size - which is tank mates... as this would derail the tank size question, I believe it would be best left out of this discussion.  I do agree with those premises for general thrive versus survive... tank mates chosen for bettas must meet a narrow band of criteria.  Not too fast to get to the food before the betta can be fed... Not too big or snarky that they would be nipping at the fins of the betta... Not too similar to the betta that the betta would feel the need to fight it to protect its territory... Not too cold water loving, so that the betta's temp needs are best met.  And a few others, none of these factors are related to tank size though, and should be left for another discussion in another place.
 
 
 
That leads us to: 
 
Girth
Activity
Fins
Scales
 
2 of which are easily identified as objective with no concern for ranges.  A torn fin or discolored scale (stress bars) would not meet the ideal.  The girth would also be fairly easy to objectively define, but for me, activity is tricky.  How active should a betta be?  Is a more active betta necessarily thriving better than a betta that meets all the other criteria but is less active?  

 

[Chad]

For fatness I specifically have certain fish in mind that I commonly see too thin. Seeing them robust and healthy makes it so obvious they are doing well. Tangs of course come to mind, as do mandarin, white cloud mountain minnows, clown loaches, and a few others that really wear their health in their girth. 

 

[eaglesaquarium]

For fatness I specifically have certain fish in mind that I commonly see too thin. Seeing them robust and healthy makes it so obvious they are doing well. Tangs of course come to mind, as do mandarin, white cloud mountain minnows, clown loaches, and a few others that really wear their health in their girth. 

 
Agreed... but we are discussing bettas.

 

[Chad]

Ha! So we are! 
 
Narrowing it down to the topic fish I think finnage, color, eye clarity, feeding, nest building, and inquisitiveness (exploring territory) are signs of thriving. 

 

[Far_King]

But blowing bubbles can also be a sign of stress in a Betta.
 
The rest I agree on.  Additional to feeding I would suggest actively looking for food and chasing it down.  A Betta that hides away and maybe has a nibble on something cannot be defined as thriving.  A Betta that investigates a potential food source that's arrived in its environment gives a better indication of well being.

 

[eaglesaquarium]

So, cycling back to the original question:  
 

• What is the optimum (or minimum) tank requirements for a betta?  

 

• What is the hard evidence (not mere anecdotal stories) that supports the claim?

 

[Ch4rlie]

I have a look for any hard evidence but this is hard to come by as so many different online sources say different theories and suggestions.
 
However i think I have found a site that is dedicated to Betta Splendens and a release given by them with guidelines set out by the AAGB and Dr Peter Burgess and this would be my evidence of a absolute minimum tank size for Betta Splendens. The result may surprise some -
 

June 2014
Press release:
 
New Betta fish guidelines released by The Anabantoid Association of Great Britain.
 
There has been a recent surge in the keeping of Betta fish (aka Siamese fighting fish; Betta splendens) in the UK, thanks partly to the wide range of colourful varieties now available. There is, however, some confusion regarding appropriate husbandry conditions for this species, particularly regarding temperature requirements.
 
In order to avoid welfare issues, a Betta care-sheet has been compiled by the Anabantoid Association of Great Britain (AAGB) in conjunction with Dr Peter Burgess and other aquatics professionals. These guidelines are aimed primarily at the general fish-keeper, particularly novices who may decide to keep a Betta as their first pet fish.
 
Press contacts:
AAGB – contact Chris Webb: [email protected]
Peter Burgess: [email protected]
 
Guidelines for keeping Betta fish (Betta splendens) in captivity
Compiled by the Anabantoid Association of Great Britain
in association with Dr Peter Burgess
 
(1) Temperature. There is a misconception that Bettas do not need heated water. In fact, these fish, which originate from South East Asia, require warm temperatures of around 24-28 C, with minimal fluctuations. Hence, the Betta aquarium requires a suitable heater that is thermostatically regulated. Bettas that are kept too cold may appear sluggish, have poor appetites, and will be more prone to disease.
 
(2) Water quality. Bettas are no different to other fish in their requirements for good water quality. Adequate filtration should be installed, but avoid filters that cause excessive surface-water movement as Bettas are surface-breathing fish from slow-moving waters, and cultivated forms can be weak swimmers. Regular partial water changes (using dechlorinated tapwater) should be undertaken. Salt should not be added, except as a temporary treatment for certain disease conditions.
 
(3) Adequate space. For a single Betta, an absolute minimum water volume of 5 litres is recommended for long-term maintenance. Smaller volumes present a significant challenge in maintaining good, stable water conditions.
 
(4) Environmental enrichment. Wild Bettas are found in densely vegetated habitats hence their aquarium should contain live aquatic plants, such as java moss and floating/surface-growing species (e.g. Ceratopteris thalictroides) for surface cover. Adequate lighting is required to keep the plants healthy. Bare tanks or bowls may cause stress as the Betta will have nowhere to escape from perceived threats. The aquarium should have a close-fitting cover.
 
(5) Proper nutrition. Feed a good quality dry diet that delivers all the Betta’s nutritional needs. Cultured live or frozen foods can also be given. Inferior diets will lead to nutritional deficiencies and digestive problems that may result in poor health and reduced longevity.
 
(6) Suitable tank-mates. A single male Betta can be kept alone or in a suitably-sized community aquarium containing placid species that won’t attack his long fins (conversely, a male Betta may attack other fish with long fins - such as a male guppy). Never keep two or more adult male Bettas together as they will fight, often to the death. Male and female Bettas should not be housed together except for breeding purposes: they are likely to become aggressive with each other either before or after spawning. Breeding Bettas requires a lot of time and experience and many tanks are needed for raising the fry (which will eventually fight) although it is undoubtedly a rewarding and fascinating process.
 
For more information on keeping and breeding Bettas and other anabantoid fishes, visit: www.aagb.org
 
http/www.aagb.org/
 
or
 
PDF
 
 
 
After I had read this, i did take a bit of a double take at the 5 litre requirement for absolute minimum size. ( 5 litres is about 1.3 US Gals).
 
While that size may be fine in some situations, for breeders for example and kept short term, then I have no particular problem with this. But would not be particularly comfortable with this for long term for betta keeping.

 

 

[eaglesaquarium]

That is quite interesting. Please note Ch4 that the target audience mentioned for these recommendations was not breeders, but "particularly novices" who have never kept a pet fish before.

This was quite a surprising result, and truly represents the first hard evidence that such a small tank would be in any way suitable as a home aquarium environment. Good find.

 

[Ch4rlie]

Yes, was aware of those guidelines from AAGB being for novice or beginners of betta keeping, i was just using breeders for an example for those who may keep bettas in 5 litres tanks short term, really as an personal preference as I think 5 litres is a very small tank for a betta to live in for it's life.
 
That is just my humble opinion, I have never kept a betta, though i may do so at some point for my boy 

 

[Baccus]

Personally I would still err on the side of a bigger tank, especially for a new fish keeper that is often going to struggle with all the confusing facts and statistics often associated with maintaining water quality. Also speaking from experience I know in Australia it is not easy to find small enough heaters for small tanks, and in most places in Australia we can really struggle with the opposite problem of tanks getting far too hot in summer. To much heat will also stress the fish and can bring on illnesses, it will also make the fighter more reliant on breathing air from the surface since warmer water carries less oxygen.

 

[eaglesaquarium]

Yes, was aware of those guidelines from AAGB being for novice or beginners of betta keeping, i was just using breeders for an example for those who may keep bettas in 5 litres tanks short term, really as an personal preference as I think 5 litres is a very small tank for a betta to live in for it's life.
 
That is just my humble opinion, I have never kept a betta, though i may do so at some point for my boy 

 
 

Personally I would still err on the side of a bigger tank, especially for a new fish keeper that is often going to struggle with all the confusing facts and statistics often associated with maintaining water quality. Also speaking from experience I know in Australia it is not easy to find small enough heaters for small tanks, and in most places in Australia we can really struggle with the opposite problem of tanks getting far too hot in summer. To much heat will also stress the fish and can bring on illnesses, it will also make the fighter more reliant on breathing air from the surface since warmer water carries less oxygen.

 
I completely agree, but it does give a very interesting 'minimum' size tank, even for a beginner.  Obviously the beginner is going to make mistakes, and so a larger volume will always help to dilute those mistakes, but that organization specifically mentioned a minimum size for beginners, which I would take as an absolute minimum for any betta keeper.  
 
So, that really addresses the 'minimum' size tank question.  It does not address the 'optimum' size tank question, which both Ch4 and Baccus are referring to.  I agree that the 5 Liter mark is likely not 'optimum'.  I'd be led to believe that 'optimum' will probably include a range of sizes from X on up to 'nature'.  
 
So, the new question is likely best described as:  "What is the minimum optimum size tank for a LONE betta?

 

[Ch4rlie]

So, the new question is likely best described as:  "What is the minimum optimum size tank for a LONE betta?

 
This is probably the main debate that Tcamos is asking for.
 
As per previous answers given already, there is a range of 'optimum' tank sizes that these folks would personally set up.
 
However, I like this statement from our own member, Wildbetta, she has written an very good article on care for betta splendens for this forum, and as she is a very experienced betta keeper and breeds rare species.
 
Size: The minimum size tank that a single betta can be kept in is 2.5 gallon. 5 gallon tanks and above are easy to heat, need to be cleaned much less often, and result in a happier and healthier betta. Contrary to popular belief, there is no maximum, and bettas do not like small spaces. Bettas kept in larger tanks are healthier and less prone to problems such as ammonia burn, bacterial infections, and obesity.
 
 
Betta Splendens Caresheet
 
I think that is a good starting point for finding what are 'optimum' tank sizes for a lone betta.