Two Controversial Questions - Small Tanks Again

[Majjie]

pardon me, but you can get any number of volumetric sizes with depths of 18" or under. they aren't always easy to come by and the corresponding widths can make placement of large, shallow tanks problematic--but they exist. i'd even venture to say that most tanks readily available in US LFS are 18" and under in depth. if you look hard, you can also find plenty of tanks that have substantial volumes and are only 12" deep. as i've said, i wouldn't be comfortable putting a betta in anything deeper than 12", but if someone wants to keep their betta in a standard All-Glass 30g with appropriate tankmates, feel free. as for deeper tanks? i personally wouldn't recommend that someone keep an air-breathing fish in a tank with a depth of almost 10 times their body length (2.5" long fish, 24" deep tank), but just because i wouldn't recommend it, doesn't mean that it isn't possible. just be sure to provide LOTS of upper-level decor/vegetation and keep an eye out for fatigue, especially in the case of older bettas more accustomed to a shallower tank.

(please also note that most descriptions of the wild bettas "rice paddy" habitat indicate that the paddies are generally in the 12" to 18" range and only reach the 20"+ range during the rainy season. to me this would indicate that even for wild-type or plakat betta splendens, shallower is generally better and is more reflective of their overall natural conditions. add in the cumulative effects of domesitic breeding for color and enlarged fins as opposed to breeding for athleticism, and it just seems excessive to keep a betta in a 2ft deep tank. i realize that this is in some ways a rehash of the the "jam jar" arguement, but there is a significant difference between a 5g and a quart.)

My apologies - you are advocating shallow - not small. I am surprised actually - that more people haven't defended tiny Betta tanks. I wasn't actually advocating a 2 foot deep tank - I was just so amazed when I saw people recommending a 2.5 gal tank for a Betta when I'd only come across my friend Victor happily swimming about in his large, deep tank. (I came across TFF and other betta owners late in my fishy development). I'm not trying to put forward an argument either way - I'm just asking if there is any evidence that small tanks are better. I can see the logic of your argument in favour of shallow - but I'm still unconvinced about small - as in 2.5 gal.

my arguement with regards to the "nano tank" was also misconstrued. i was in large part trying to echo T and Fella's comments regarding unexpected sources of waste. (if you still don't believe that these tiny waste spikes are real, please go read CFC's post about the death of his first paradise threadfin catfish.) but what i was mostly trying to explain is why we generally try to discourage tanks under 5g in size. there aren't many fish that would be appropriate to stock in a tiny tank without having to make a special order. but because you can get good filters and appropriately sized fish if you're willing to spend the money, there are a lot of people on here who keep nanotanks and they get a lot of applause. as for why they do waterchanges at least once a week, well CFC just hit that nail on the head.

I didn't misconstrue your argument - I simply applied it to my question. I didn't ask why people generally try to discourage small tanks - I know perfectly well why (as I thought I had made clear in my colourful warnings ). I asked why - if you only kept appropriately small fish (however difficult to get hold of) - a small tank would be inherently more unstable than a larger one and why people say that they require more maintenance. Changing the water once a week doesn't represent a higher level of maintenance - many of us do that with much larger tanks. Was CFC's paradise threadfin catfish in a tiny tank? I thought the point there was that the fish was particularly sensitive - nothing to do with the size of the tank - but I could easily be wrong I haven't actually looked it up

I have conceded several points:

1) I'd need a reasonably efficient filter (but then I'd want that on any size tank that I bought)
2) I'd need a couple of little tiger shrimp to clear up uneaten food
3) I'd need to have a bottle of distilled water to top up the tank - unless I could get a tank with a close fitting lid (I'm definitely going to have a look at these tanks!)
4) I'd need to be careful about paint fumes/polish etc. (but I am anyway - around my bigger tanks)

Doesn't sound that different to a big tank to me! [Accepting all the caveats about the right size and sort of fish]

 

[Majjie]

Question 2
I haven't seen anyone on here recommend keeping guppies in 1 gal tanks - or danios in 5 gals.

Oh, I didn't say on here- but that doesn't make any difference. Just because no-one on here says it, doesn't mean it's wrong.

Actually - I think if no-one on here said something was right - then I'd believe it was wrong! It's one of the characteristics of this forum - plenty of different opinions!

But I have seen them recommend keeping Bettas in very small tanks.

Very small compared to what? A 20g? The cups most were raised in?

To my mind 2.5 gal is very small. My instinct would be that a Betta should have 5 gal minimum. But that's why I'm asking. What evidence is there that smaller is ok.

Some of you have told me that you wouldn't keep Bettas in a bigger community tank because they might encounter inappropriate tank mates - but what if they didn't? What if you designed your larger tank around your Betta with peaceful companions (my friend's "Victor" was in with black neons, rummy nose tetras and dwarf pencil fishes - the only aggression was from Victor himself - and the tetras just seemed to laugh at him, because they could swim ten times as fast).

The point is, all fish are different. Many bettas will attack *any* other fish, and many 'peaceful' fish that you describe will certainly cause stress. Bigger tanks are fine- if you've only got a betta, possibly a few uninvasive bottom dwellers.

Actually - I don't think that is the point - many gouramis, some angelfish and probably lots of fish I'm not familiar with, are just as tricky to accomodate in a community tank but nobody suggests that it can't be done - only that you need to be careful. Many people also keep Bettas in community tanks. If (and only if) that is the only reason for keeping them in tiny tanks then isn't that just being lazy? I'm only asking.

I'm aware that Bettas seem to prefer areas near the water surface - but there's plenty of that in a bigger tank.

Which also has a lot of current near the surface for maximum oxygen diffusion.

I guess that depends on the tank and the equipment in it. Are you saying that as long as a large enough area of the surface doesn't have a very strong current - then a large tank would be fine?

Many of you are of the opinion that Bettas are betta off (sorry! ) in smaller tanks - but you don't have any evidence

But then, there's little evidence for bettas in large (ie, 10g+) tanks either. All both sides of the coin have is 'but they are happier in x'- you can talk about water quality and so on, but the fact is that it's often easier to keep good water quality in a smaller tank as the water changes are large and frequent.

Am I missing something here? Surely the only reason for doing large and frequent water changes in a small Betta tank is because the tank is small - often has no filtration - and has a large fish in it. If the Betta was in a large tank with adequate filtration - water quality wouldn't be any more of an issue than with other "fancy" fish like male guppies or dwarf gouramis.

If there's a lack of evidence either way - what is the justification for very small tanks? Surely the benefit of the doubt should go to the larger tank.

Sorry I'm not intending to pick on you OohFeeshy - I just wanted some clarification - and you're the only one who's put up a fight

 

[Jozlyn]

You are forgetting the scale factor in a nano tank. The ration of surface area to volume is going to be higher. Take a 6x2x2, that's 150 gallons with 12 square feet (1728 sq in) of surface area.

Next take a 16x8x8, that's 3.69 gallons with 128 sq in of surface area.

The larger tank has 11.52 sq in of surface area per gallon, whereas the smaller tank has 34.69 sq in of surface area per gallon. This means that the nano tank will suffer far more quickly the ill affects of evaporation (pure water will evaporate leaving the dissolved chemicals behind). This will lead to dissolved bodies accumulating at an increased rate, thus making water maintenance a more regular (if in smaller quantities) event to control nitrates and dissolved organics.

Even if you scale down the bioload accordingly, the maths of area vs volume will cause you problems, as it does with nano reefs which require topping off with RO water far more frequently than larger systems to avoid the salinity going off target.

Ok - I admit it - I hadn't though about evaporation! All my tanks have close fitting lids and I don't get much evaporation from them - certainly not within a week. I've no idea whether 10litre tanks with lids are available. I'll have to have a look next time I'm in the lfs. If not, I guess it's not too much trouble to pour a little bit of water in during the week. It wouldn't need to be RO water for a fresh water community tank - as long as normal water changes are carried out weekly. And I never said the maintenance wo
uld be less than a normal tank - just that I didn't see why it should be more!

You can get 10lt tanks in Australia with close fitting lids, I have one, I have only very very minimal water evaporation.

 

[OohFeeshy]

Actually - I think if no-one on here said something was right - then I'd believe it was wrong! It's one of the characteristics of this forum - plenty of different opinions!

Indeed- do not forget all aspects of fishkeeping are (when it boils down to it) opinions. Many people feel very strongly fish should not be kept as pets at all- in their opinion, even the largest standard (well, not that large or that standard, but it's the most common large tank size) tank, a 6x2x2 is far too small to keep fish when you consider their natural habitat.

To my mind 2.5 gal is very small. My instinct would be that a Betta should have 5 gal minimum.

To your mind In my mind, 2.5g is plenty big enough for many species- although I do know of more species than most people that are that small. Don't forget also dimensions come into play- 2.5g tanks are *usually* a 12x8x8, and easy to obtain, although certainly in the UK 5gs come in a wild variety of dimensinos with many tall hex tanks having that volume. When you compare dimensions (I beleive a standard 5g is something like 15x10x10, but I have no idea),the 5g adds only a couple of inches in each direction. And often, the dimensions are more important than the volume.

Actually - I don't think that is the point - many gouramis, some angelfish and probably lots of fish I'm not familiar with, are just as tricky to accomodate in a community tank but nobody suggests that it can't be done - only that you need to be careful. Many people also keep Bettas in community tanks. If (and only if) that is the only reason for keeping them in tiny tanks then isn't that just being lazy? I'm only asking.

Oh, fair enough- bettas share many aggressive traits with many other fish- but you have to remember that bettas have been bred to, basicly, kill another male on sight. Well, not kill nessecarily- but that's not the point. Under the umbrella of 'male' can come anything- other bettas, gouramis, tetras, garras, whatever. They're not overly perceptive. To be honest, using the reason 'many people keep bettas in community tanks' is heading down the long and treacherous road to ruin- think of all the appaling things 'many people' do- doesn't make it right. Many people keep goldfish in vastly innapropriate tanks, bettas in really small containers, and suchlike.

I'm aware that Bettas seem to prefer areas near the water surface - but there's plenty of that in a bigger tank.

Which also has a lot of current near the surface for maximum oxygen diffusion.

I guess that depends on the tank and the equipment in it. Are you saying that as long as a large enough area of the surface doesn't have a very strong current - then a large tank would be fine?

Am I missing something here? Surely the only reason for doing large and frequent water changes in a small Betta tank is because the tank is small - often has no filtration - and has a large fish in it.

Large, not really. Unless you've got a giant in a tank that small (which is unlikely), most length is just finnage. They're small, even compared to tank size, and lazy (generally). Bioload, in actuallity, deterioates water quality very slowly. On occasions I've left my 2g tanks (which, by the way, are selected for dimensions- 12"x6x6, maximising length and width to volume ratio) without water changes for two or three weeks, and returned to a healthy, active fish with no 'off' water readings. Large frequent water changes are beneficial even if in a 10g filtered tank- they encourage bubblenesting and suchlike.

If there's a lack of evidence either way - what is the justification for very small tanks? Surely the benefit of the doubt should go to the larger tank.

Justification is whatever the keeper thinks It's like asking what your justification was for keeping fish at all- there's no right or wrong answer, just what you think (which is probably something along the lines of they're interesting, eductional etc.).

Sorry I'm not intending to pick on you OohFeeshy - I just wanted some clarification - and you're the only one who's put up a fight

No problem. I'm just voicing others opinions (since not many other people can be bothered to post). Personally, I'm not bothered either way- IMO, if the betta is happy and healthy, tank size makes little difference.

 

[pica_nuttalli]

my arguement with regards to the "nano tank" was also misconstrued. i was in large part trying to echo T and Fella's comments regarding unexpected sources of waste. (if you still don't believe that these tiny waste spikes are real, please go read CFC's post about the death of his first paradise threadfin catfish.) but what i was mostly trying to explain is why we generally try to discourage tanks under 5g in size. there aren't many fish that would be appropriate to stock in a tiny tank without having to make a special order. but because you can get good filters and appropriately sized fish if you're willing to spend the money, there are a lot of people on here who keep nanotanks and they get a lot of applause. as for why they do waterchanges at least once a week, well CFC just hit that nail on the head.

I didn't misconstrue your argument - I simply applied it to my question. I didn't ask why people generally try to discourage small tanks - I know perfectly well why (as I thought I had made clear in my colourful warnings ). I asked why - if you only kept appropriately small fish (however difficult to get hold of) - a small tank would be inherently more unstable than a larger one and why people say that they require more maintenance. Changing the water once a week doesn't represent a higher level of maintenance - many of us do that with much larger tanks. Was CFC's paradise threadfin catfish in a tiny tank? I thought the point there was that the fish was particularly sensitive - nothing to do with the size of the tank - but I could easily be wrong I haven't actually looked it up

I have conceded several points:

1) I'd need a reasonably efficient filter (but then I'd want that on any size tank that I bought)
2) I'd need a couple of little tiger shrimp to clear up uneaten food
3) I'd need to have a bottle of distilled water to top up the tank - unless I could get a tank with a close fitting lid (I'm definitely going to have a look at these tanks!)
4) I'd need to be careful about paint fumes/polish etc. (but I am anyway - around my bigger tanks)

Doesn't sound that different to a big tank to me! [Accepting all the caveats about the right size and sort of fish]

i have a suspicion that we're trying to say the same things, just from different angles it does seem that, given compliance with all 4 points, that a nano (or even a pico) tank should require about the same maintenance as a larger tank. (you're right that at least once a week isn't higher level of maintenance; that was a poorly worded way for me to say "they probably do changes more than once a week, but could in theory skimp sometimes". ) although i would argue that point 3 is a substantially increased degree of maintenance, as the only tank that i ever need to "top off" is my 10g--which has a screened top, making it essentially open air. and even that tank only loses about a half-gallon a week.

it seems funny to me to be having both of these discussions simultaneously, as i've been desperately wanting to recreate Fishkillernomore's Zen betta-nano for months now do you have an argument against keeping a betta in a 2-5g planted, given that all 4 of the maintenance points are attended to? (although the shrimp are probably not an option given that my betta is known to be a snail eater )

 

[Majjie]

Apologies for my delay in replying - and for bringing this thread up again (I've been trying to get some work done over the last two days)!

Thanks to everyone who posted. My thoughts are these:

Question 2
I entirely agree with you OohFeeshy that all aspects of fishkeeping are largely matters of opinion. When I was young (many - many - moons ago ) - it was considered quite acceptable to keep goldfish in bowls and very small tanks. I've seen goldfish, in a 5 or 10 gal tank, that have grown so huge they can only just turn round. I myself kept five or six goldfish in what must have been about a 15 gal tank. This is now considered totally unacceptable - for people who do some research into suitable conditions for their fish. I just wonder whether - in many more moons - keeping bettas in very small containers will be equally unacceptable (except for breeding).

I admit that saying "many people keep bettas in community tanks" wasn't a good argument for doing so! I should have said that many people keep bettas successfully in community tanks - without any aggression problems. Evidence did indeed appear in this thread. Supercoley 1 keeps a betta successfully in a large deep community tank and, much more tellingly, Darkmoon Bettas, who breeds bettas, gives them a holiday in a larger community tank to perk them up and finds that her "pet" bettas living with companions, in larger tanks, tend to live longer. Seems quite persuasive to me!

The only evidence that bettas dislike larger tanks came from t.ropical - but his betta was only in a temporary tank - so it doesn't really apply to normal living conditions. There was some very convincing argument for keeping bettas in shallow tanks, rather than deep ones - but no evidence. Only opinions.

I fully admit that evidence is hard to come by. It's asking a bit much, for a betta keeper to invest in a large tank and put a lot of effort into setting up suitable conditions and a compatible community for a betta - just to prove a point. Especially if it might show that the methods he or she has been using up to now were detrimental to the fish. I have absolutely no doubt that people who keep bettas in tiny tanks care a lot for their fish!

But that's why Darkmoon Betta's evidence is so compelling. She has tried both small and large tanks - and found that larger tanks - with companions - are best. Lljdma has also kept bettas in both large and small tanks - but she didn't find any difference as far as the welfare of the fish was concerned.

Seems to me that what evidence has been offered is either neutral or supports the thesis that larger tanks would actually be better. None supports the idea that smaller tanks are better.

Having said that - and going back to OohFeeshy's comments. I entirely agree that fish health and happiness is quite a subjective topic. I believe that many fish keepers do have a feel for when their fish are feeling good which - though not evidence, exactly - should perhaps be taken into account. The danger lies with people who are not familiar with fish and don't realise when a fish is acting abnormally for the species.

And in the much longer term ....... it may indeed be the case that keeping any fish in tanks in the home will be considered unacceptable (I shall be long gone, though - it's only the real youngsters amongst you who will have to cope with that )


Question 1
Seems to me that very small tanks are fine - and need no more maintenance than larger tanks as long as:

1. 
   the occupants are a suitable size - and WILL REMAIN SO
   the filter is not a crappy one (it could be tested with ammonia - when first setting it up)
   there are some live plants growing in it - to help stabilise the conditions
   the tank has a tight fitting lid (or you are prepared to do a bit of extra maintenance by topping up with pure water)
   you are very careful about excess food (or have a few of the very small shrimp to clean it up)
   you are similarly careful about external contaminants like paint and polish

I know I've already said most of this - but since keeping inappropriate occupants in small tanks is such a problem in the hobby I thought it worthwhile repeating it.

I shall, of course, pop over to Australia - to pick up a tank with a close fitting lid - like Jozlyn's
And in reply to pica_nuttalli; I don't have any argument with keeping a betta in a 5 gal tank - I personally think that 2.5 gal is too small - but I wouldn't stop anyone else having a tank that small for a betta - I'm not a fish tank vigilante! I know it seems odd discussing these two topics together - the whole point is, that I think a 2.5 gal tank could be entirely appropriate with the right fish in it - it's just that for me a betta isn't the right fish.

Oh and I love fishkiller_nomore's Zen betta tank (even though it's only 4 gal ) - having now looked at it - I'd not seen it before. (If I win the lottery I'll just spend half my time on here - looking around and improving my fishy knowledge - and the other half toying with my tanks - and telling the staff which ones need maintenance )

 

[OohFeeshy]

I just wonder whether - in many more moons - keeping bettas in very small containers will be equally unacceptable (except for breeding).

Oh, definately- minimum size opinion seems to be increasing worldwide, not just for bettas but for many species. Whether it's to do with less of the really appaling betta tanks on the market (such as the betta hex ones, and ones similar in size), a decrease in price of larger tanks (when I say larger I mean the 2.5-10g range), better availability or another factor, I'm not sure- maybe it's to do with the latest fashion in nano planted tanks (while you can't do much with a betta hex, a betta is one of limited options for, say, a 2.5g). Who knows...

I should have said that many people keep bettas successfully in community tanks - without any aggression problems.

That has about the same weight as the previous statement You could consider many ideas of 'successful' in many situations- successful keeping of goldfish with tropical, successful keeping of two male bettas, successful keeping of mbuna in softwater setups- again, doesn't prove anything. You could go to the betta forum and get everyone's lists of successful betta keeping practices- there's equal or similar amounts or 'success' in 1/2gs, 1gs, 5gs, 10gs, whatever.

Darkmoon Bettas, who breeds bettas, gives them a holiday in a larger community tank to perk them up and finds that her "pet" bettas living with companions, in larger tanks, tend to live longer. Seems quite persuasive to me!

Again though, one person, and an opinion which conflicts with other's opinions. Put any of my guys/gals in the 2ft community tank, they'd go off their head biting other fish and barely be able to cope with the current.

There was some very convincing argument for keeping bettas in shallow tanks, rather than deep ones - but no evidence. Only opinions.

But it hardly needs to be classed as an opinion bettas do better in shallower tanks, IMO- you seem to assume shallow means small, which isn't always the case. Although if it does, a shallow tank means a longer and wider tank- more swimming room to volume. And again, opinions are what count

I fully admit that evidence is hard to come by. It's asking a bit much, for a betta keeper to invest in a large tank and put a lot of effort into setting up suitable conditions and a compatible community for a betta - just to prove a point.

Not really a very good experiment though- all bettas are different, and while some certainly tollerate other fish, some go loopy. Some prefer smaller tanks to larger tanks (if you search there are quite a few instances of a betta being upgraded and being lethargic, not eating etc. in the larger tank, only to begin swimming around happily in the smaller tank), some vice versa. Some aren't aggressive, some are extremely aggressive.

 

[dwarfgourami]

I don't seem to be getting much evaporation from either my 19 ltr or my 25 ltr- the water has never gone down noticeably when I come to do my water change. Fair enough, the 25 ltr is a hex (horrible shape!), with only limited surface area, but the 19 ltr has very similar proportions to my larger tanks-and as little evaporation as they do. This being the case, and assuming that I only keep nano fish, should I expect more problems than in a larger tank?

Oh, and why are we talking about bettas all the time? What about some nice small fish for a change?

Also, why is the assumption that one is going to overfeed a few fish in a small tank more than plenty of fish in a large tank? Can't I just count the flakes that go in? Easy enough to count to 3 (fpr 3 male guppies).

 

[OohFeeshy]

I don't seem to be getting much evaporation from either my 19 ltr or my 25 ltr- the water has never gone down noticeably when I come to do my water change.

That is true, and a point I forgot to mention- the only tank with noticable evaporation is the one that's sat on top of the hood of my 2ft, which makes it quite warm at times. The rest are fine

Oh, and why are we talking about bettas all the time? What about some nice small fish for a change?

Dunno, I think that was the main query of the OP. Although fish for small tanks can be hard to obtain, the smallest many people can get are neons and similar.

 

[Majjie]

Darkmoon Bettas, who breeds bettas, gives them a holiday in a larger community tank to perk them up and finds that her "pet" bettas living with companions, in larger tanks, tend to live longer. Seems quite persuasive to me!

Again though, one person, and an opinion which conflicts with other's opinions. Put any of my guys/gals in the 2ft community tank, they'd go off their head biting other fish and barely be able to cope with the current.

There is a slight difference - Darkmoon Betta is reporting her experience in keeping bettas in both small and large tanks. You seem to be saying that you think your bettas would go off their heads - not that you've tried it and they did. So, one is opinion based on evidence, the other is just opinion.

There was some very convincing argument for keeping bettas in shallow tanks, rather than deep ones - but no evidence. Only opinions.

But it hardly needs to be classed as an opinion bettas do better in shallower tanks, IMO- you seem to assume shallow means small, which isn't always the case. Although if it does, a shallow tank means a longer and wider tank- more swimming room to volume. And again, opinions are what count

I disagree - opinions only count if they are based on experience (i.e evidence) - not if they are based on hearsay or a hunch. I have, as a result of this thread, realised that shallow and small may be very different, as far as keeping a betta is concerned. Nobody, however, has presented any evidence of that. Nobody has said - "I kept the same betta in a shallow tank and then in a deeper tank with the same footprint and he seemed much happier in the shallow one because .........."

I fully admit that evidence is hard to come by. It's asking a bit much, for a betta keeper to invest in a large tank and put a lot of effort into setting up suitable conditions and a compatible community for a betta - just to prove a point.

Not really a very good experiment though- all bettas are different, and while some certainly tollerate other fish, some go loopy. Some prefer smaller tanks to larger tanks (if you search there are quite a few instances of a betta being upgraded and being lethargic, not eating etc. in the larger tank, only to begin swimming around happily in the smaller tank), some vice versa. Some aren't aggressive, some are extremely aggressive.

On the contrary - it would be a very good experiment - as long as enough people did it - which I fully admit is unlikely.

I haven't got the time to go trawling through the betta forum for examples of bettas that seemed to do better in smaller tanks - the trouble with opinion is that it's so seldom based on evidence. If you condition a betta to living in a tiny tank with no companions - it is highly likely to be freaked out by a big tank and other fish. Doesn't mean to say it wouldn't settle down and be very happy if allowed to acclimatise.

I asked for any evidence that bettas preferred to live in smaller tanks - and got none!
That may well be because nobody with evidence could be bothered to answer - but that's just the way it goes

I don't seem to be getting much evaporation from either my 19 ltr or my 25 ltr- the water has never gone down noticeably when I come to do my water change.

That is true, and a point I forgot to mention- the only tank with noticable evaporation is the one that's sat on top of the hood of my 2ft, which makes it quite warm at times. The rest are fine

Oh, and why are we talking about bettas all the time? What about some nice small fish for a change?

Dunno, I think that was the main query of the OP. Although fish for small tanks can be hard to obtain, the smallest many people can get are neons and similar.

Seems like I can cross off evaporation as a big problem then.

And yes - I started off the post with two questions - one about small tanks and one about bettas in small tanks. Just trying to confuse you all

 

[OohFeeshy]

There is a slight difference - Darkmoon Betta is reporting her experience in keeping bettas in both small and large tanks. You seem to be saying that you think your bettas would go off their heads - not that you've tried it and they did. So, one is opinion based on evidence, the other is just opinion.

Ah, says you Who's to say I haven't tried it? I have, in fact, with pretty much all of them at some point. So there's a whole *heap* of evidence, when you include all the bettas I've kept over the years Only one was fine with it, but I withdrew him when he kept hiding in the rocks and worrying me...