Two Controversial Questions - Small Tanks Again

[pica_nuttalli]

actually, Question 1 is really just the premise behind all "nano" planted tanks. but the reason that we typically say that "bigger is better" is that most common fish are far too large for the nano set-up you described. you really can't keep anything larger than a female guppy without violating the situation you described previously in terms of spatial proportions.

the biggest obstacle to a low-maintenance tiny tank is the difficultly in providing "adequate filtration". most filters sized for smaller aquariums really aren't very efficient; the HOBs described by lldj aren't readily availble and can tend to be pretty pricey when you do find them. once you hit around 5g, the filtration options improve but the filters included in most kits are cheapie and again, inefficient. (of course, low-quality kit filtration is pretty much the norm for all sizes). in larger tanks, these inefficiencies are buffered by the increased water volume such that brief spikes in waste levels are dilluted to a safe level until the filter is able to catch back up.

as for Question 2, it isn't so much the volume of the tank as the height that really effects bettas. the need to define and protect a territory can be offset by careful choice of decor limiting the line of sight. but nothing can change the fact that a betta's primary means of respiration is the labyrinth organ. i personally would hesitate to keep a betta in anything deeper than 18" just because that's a long way to swim for a breath of air. a weakened betta might not make it and the increased "rise time" would probably decrease the quality of rest for a betta in a deeper tank. (i think this is supported by the common anecdotal evidence of how bettas prefer to "sleep" in vegetation or on decor within just a few inches of the water's surface. while such an arrangement could also work in a larger tank, i don't think that we should obligate the betta to sleep in a certain place just because we want to keep him in a deeper tank.) all that being said, i don't see anything wrong with keeping a betta in a 10g or any other 12" deep tank provided that appropriate tank mates have also been selected.

 

[OohFeeshy]

Bettas- as many have already mentioned, all non-wild variants (even plakats, although not in the same way) are inbred, can be quite weak (while hardy fish, often conditions they were raised in/kept in at LFS aren't good [often cups in the US, tanks with boisterous tankmates in the UK]), are very terratorial and aggressive (ideally kept alone, larger tanks often encourage people to keep bettas with stressful combinations of other fish, and obviously, territory [often bettas will attempt to hold the whole tank as teritory]) and obviously the colourful, long finned variations are prone to being attacked and make it difficult for the fish to swim long distances or in a current.

Besides which, 'small' is relative- compare the (now usually) recomended 2.5g with the bettas size, bioload and activity and larger fish- oscars, balas, clown loaches, etc.- with their reccomended minimum tank size. While an oscar's minimum tank size (4x2x2) is just 4x it's length and twice it's width, a 12x8x8 betta tank is, excluding tail on long finned varieties, 5 or six times the bettas length and 3.5-4 times it's width. Add to that low bioload, low oxygen demand (due to the labyrinth organ) and suchlike and you see where proportion comes in. Of course, it's all down to personal opinion- many people find it perfectly acceptable to keep guppies in tanks around 1g, tetras in tanks around the same, danios in 5gs (have you seen the stocking levels reccomended for lab zebrafish?) and similar.

 

[Majjie]

Question 1
I agree that planted nano tanks fit into my criteria but their owners often stress the fact that they carry out much higher levels of maintenance and water changes than in "normal" tanks. Like I said - I suspect that this is as much for the plants as for the fish - because most nano tank owners are plant enthusiasts. My hypothetical low maintenance micro tank wouldn't require any more maintenance than a larger tank.

I'd quite agree that bigger is better for most fish species - the fish for my tank would be restricted to the smaller rasboras, neon tetras or similar small tetras - maybe dwarf pencil fish and the dwarf cories. Guppies wouldn't fit the criteria - definitely not females anyway - maybe two males, if they didn't fight, because they're smaller. But saying that such a tank isn't suitable for most of the common species of fish isn't the same as saying that it isn't suitable for any fish!

Buffering capacity is a bit of a red herring - if we assume that only small fish are kept. The waste produced would be proportional to the size of the tank and the buffering capacity available. My whole theory is based on reduced scale.

I guess that, without trying it, I can't argue with those of you who say that the filtration wouldn't be adequate. Having carried out fishless cycling on my 30 litre tank - and seeing first hand exactly how much ammonia the filter could cope with - I find it difficult to understand why adequate filtration would be a problem - but I've never tried smaller tanks. It awaits the experiment!

Question 2
I haven't seen anyone on here recommend keeping guppies in 1 gal tanks - or danios in 5 gals. But I have seen them recommend keeping Bettas in very small tanks. Lab conditions are rather different - they are only trying to avoid distress in the fish - not trying to give them a long and happy life. I don't know anything about lab fish but I have had experience of lab rats and mice - nobody's worrying about long and happy lives because it's illegal not to kill them after the experiment has been carried out! Rather different to keeping pets.

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).

I'm aware that Bettas seem to prefer areas near the water surface - but there's plenty of that in a bigger tank. pica_nuttalli talks about not wanting to"obligate the betta to sleep in a certain place just because we want to keep him in a deeper tank" but surely that's turning the argument on it's head. In a deeper tank the betta can choose - in a shallow one there is no choice.

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

 

[lljdma06]

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

Who said that in this thread? I know I didn't say that, in fact, I was supportive of either scenario. I at least quoted sources.

 

[andywg]

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.

 

[SuperColey1]

Ooh the Betta debate again. lol

My Tank 125Ltr 18" inch deep, overstocked, heavily planted, filter on full although through a spray bar, school of tetras, school of danios, 4 mollys.

So in theory:
He should be tired all the time from the size of the tank (seems to swim a lot, so must just be an energetic lad)

He should be aggressive, because there are so many fish in there. (Only flares when the mollies are mating, and even then not for long before going about his business again, ans sometimes hangs out peacefully with them when they aren't mating)

He should have no fins left due to the Tetras and Danios nipping him non stop (Never seen this happen and in the 4 months since I bought him as a slightly ragged finned fish, he has become a beautiful fully healed Veiltail)

All in all. works for some, and others are just born lucky. Its a very peaceful tank really. If the Bettas Grumpy and charges at the mating mollys, they just move awway and he goes back to building his bubble nest for his imaginary wife, or resting on top of the filter, or eating snails eggs, or investigating the dark parts in the bottom of the tank.

I think he likes his larger than normal tank, with other fish pals to hang out with sometimes, and plenty of corners to go away and have his afternoon nap.

Long live community Bettas.

 

[t1tanrush]

1) I'm no expert, but a lot of people say these things, doesn't mean its the set law. I have ~50 minnows in a 10 gallon with an african clawed frog, with regular cleaning, its not a problem, although they are feeders, but I always have new coming.
2) Bettas like room, A betta in a 10g is happier than a betta in a 1g. I've seen it myself. Most betta keepers have them in 5gs. Although, I'm pretty sure that putting a betta in a large (20+) is not going to affect its health, most people would call it a wasted tank, because bettas are aggressive, and most fish such as tetra that you would put in there, would nip their fins. To me its just an accumulation of random thoughts.

Always best to decide for yourself on tank sizes etc.

 

[SuperColey1]

seconded. This hobby has no set rules although I must there are some very useful guidelines, but often mistakes teach us more than we could ever research.

(I guess I'm saying that I knew you couldn't put 2 male bettas in the same tank, and when I rehomed the glolights and danios for someone, I didn't think. ooh they might nip my betta, I guess I got lucky, but as always there are exceptions to the rule and what works in 1 tank can go disasterously wrong in another)

 

[Darkmoon Bettas]

I'm a "betta person"--I've bred them casually for many years. (Never got into the show circuit, but I've worked with some pretty nice fish as opportunity presents itself.) When breeding, growing out, and jarring fry, yes, I use the traditional smaller jars and frequent water changes, and it works well.

That said, I've also ALWAYS had "pet" bettas--non-breeding quality, retired breeders, rescues, etc--in any of my community oriented tanks that will support them, and they've thrived, often been longer lived, more active (without being paranoidly on guard), and had more personality with other tankmates to interact with, than some of my breeders, even the ones being pampered in 2.5's all to themselves. They only go with suitable companions, of course--no bettas go in the tank full of kribensis or apistos, but tanks with (some) danios, appropriate tetras, appropriate livebearers (no guppies!), rasboras, and other like-tempered fish all have a betta in them.

In fact, bettas that are "off"--listless, seemingly depressed, lethargic, but with no apparent illness of any kind--often get swapped out with one of my pets and get a "vacation" in a community tank. I do this pretty often with males who seem to get the post-fry-tending depression when I've pulled them from their spawns. It snaps them out of the sulk, perks them right up, and they go back to their happy, healthy selves much more quickly then males left in smaller containers (from 1/2 gallon jars - 2.5 gallon filtered tanks) alone with no company.

 

[Majjie]

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

Who said that in this thread? I know I didn't say that, in fact, I was supportive of either scenario. I at least quoted sources.

No - you weren't one of the many llj. I suppose I was sort of thinking about the forum as a whole - not just this thread - but Miss Wiggle did say that putting Bettas in a big tank could "over exert them"; t.ropical wouldn't risk putting one of his Bettas in more than a 2 gal tank and pica_nuttalli wouldn't use a tank deeper than 18 inches and would prefer 12 inches. To me - they sound like opinions that tend towards smaller is better!

 

[Majjie]

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 would be less than a normal tank - just that I didn't see why it should be more!

 

[Majjie]

seconded. This hobby has no set rules although I must there are some very useful guidelines, but often mistakes teach us more than we could ever research.

(I guess I'm saying that I knew you couldn't put 2 male bettas in the same tank, and when I rehomed the glolights and danios for someone, I didn't think. ooh they might nip my betta, I guess I got lucky, but as always there are exceptions to the rule and what works in 1 tank can go disasterously wrong in another)

Yes - I agree with you both.
I wasn't really talking about the stocking "rules" (well - not in this thread, anyway ). I was questioning the principle - which seems to be widely accepted - that small tanks = much more maintenance (whatever fish are kept in them).

 

[CFC]

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 would be less than a normal tank - just that I didn't see why it should be more!

Any water used for topping up after evaporation should be either R/O or distilled water otherwise you will eventually lead to the tank having higher than usual mineral content since only pure H2O evaporates leaving its mineral content behind. This can lead to the water becoming harder and more alkaline over time which most tropical fish will find uncomfortable.

 

[pica_nuttalli]

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 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.

 

[OohFeeshy]

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.

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?

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.

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.

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.