Needing Help Deciding on What to Put in 6.6g/25l Tank! (see post #27 for NEW information on poll)

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What to Stock 6.6g/25l Tank With (please read below!)

  • Ind.---Betta splendens

    Votes: 3 30.0%
  • Ind./Pair/Trio--Wild-type Betta (B. imbellis, albimarginata, rubra, etc.)*

    Votes: 2 20.0%
  • Pair---Parosphromenus species (P. quindecim, filamentosus, linkei, etc.)

    Votes: 0 0.0%
  • Pair---Sparkling Gourami (Trichopsis pumila)*

    Votes: 3 30.0%
  • 8-12---Small Rasbora Shoal (Microdevario, Microrasbora, or Boraras species)

    Votes: 1 10.0%
  • 3-7---Scarlet Badis (Dario dario)

    Votes: 0 0.0%
  • Ind.---Dwarf Puffer (Carinotetraodon travancoricus)*

    Votes: 0 0.0%
  • 4-5---Dwarf Cory (Corydoras hastatus)*

    Votes: 0 0.0%
  • Pair/Trio---Killifish (Pseudepiplatys annulatus or smaller Aphyosemion sp.)

    Votes: 1 10.0%
  • Colony---Caridina sp.

    Votes: 1 10.0%
  • Pair/Trio---African Dwarf Frogs (Hymenochirus sp.)

    Votes: 1 10.0%
  • 4-6---Indostomus crocodilus OR Indostomus paradoxus

    Votes: 0 0.0%
  • 2-4---Asian Stone Catfish (Hara jerdoni)

    Votes: 0 0.0%
  • 4-6---Parasphaerichthys lineatus

    Votes: 0 0.0%

  • Total voters
    10
  • Poll closed .

gilltyascharged

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Hello! After about a month of using it as a plant holding tank, I've decided that it's time to do something with my somewhat unstocked (see note below) 6.6g/25l tank. Previously I have had B. splendens, an Endler or two, and ADFs in this tank, and want to branch out a tad bit.

While I don't have any definite numbers regarding water parameters as of right now, here is what I am working with as far as setup and parameters go:

  • Dimensions are 16"/41cm x 8.6"/22cm x 11.2"/28cm
  • Temperatures from 68-82 F---68 F being room temp, adjustable submersed 50w heater can easily go higher though if need be
  • Filtration: Either a Marineland Penguin 100B (oversized HOB) OR Aquarium Co-Op sponge filters in various sizes
  • Local tap water runs HARD (19.61-30.82 dH, according to city website), but I also have access to RO water
  • Homemade blackwater extract (oakleaf) on hand
  • Chemical pH neutralizer and increaser, as needed
  • Plants (max 2-5 choices): Anubias barteri AND barteri 'nana'), Java moss, Java fern, Crypt wendtii and parva, Dwarf Hair Grass, Apongeton, Frogbit, Duckweed, Vallisneria, Pothos, Spider plant
  • Substrate is currently a large (1/4 - 1/2"), smooth, light-colored gravel---other options include smooth, natural gravel (<1/4"), and pre-soaked oak leaves
  • Note: this tank has been up and running for around ~2-3 years now, so is definitely cycled and seasoned, lol. While the nitrate cycle appears to be in order, I still need to perform water testing in order to double-check that everything is doing well. As mentioned above, the tank currently is holding a handful of plants purchased a week or two ago, as well as a single Bronze Cory waiting on an upgrade (providing parents allow, a nice 20g long with some more cory friends!). Air-powered sponge filter has been running in tank for nearly a month, and other than some healthy algal growth everything seems to be doing well.

If you think I should either add or remove an option, please let me know! I have put options that I have heard mixed opinions over on the forum with a small (*), as a heads up that I am aware that, while some think it could work, others are strongly against it. Again, most of these ideas come from scouring various websites and AqAdvisor (a helpful, but imperfect system), and I would love to hear from those who are more experienced in this area of fishkeeping.

Thanks in advance,
Gilltyascharged
 
Corys are better in larger groups and they need soft sand for a substrate.
 
I just wanted to clarify on the current Bronze Cory's situation: The cory in question was originally purchased by my father back in May of this year (around seven months ago) with two other cories. He had originally put them in a 28g bowfront aquarium with a juvenile OB peacock cichlid and three Red-Eyed Tetras, and, I'm sure to nobody's surprise, the cories were harassed horribly. After a few weeks of protesting to move them to my 6.6g (my house has a strict "don't touch the tanks rule"), my parents finally gave in when my mother finally came down and realized that I wasn't exaggerating--all three cories were frantically scurrying about with tattered dorsal fins as the 2" mini-terror chased them about.

Fast forward a few months, and currently the biggest cory is the only one left. I have been trying to convince my parents to let me get a 10g tank at the very least (as much as I know he/she'd love some more cories to shoal with, I don't feel comfortable adding more into a tank that small), but currently my dad is firmly against any more tanks in the house until I move out---apparently vacuuming a dirty, filth-covered, hasn't-been-cleaned-in-three-months tank violates the "seriously, do NOT touch the tanks rule"---not to mention that constantly bringing up the need for a larger tank for a growing peacock gets on his nerves....go figure.

However, I am happy to say that my persistence (or nagging, as my dad calls it) has not only led to a larger, happier school of tetras, but a 75g tank (kindly donated by my dad's great-uncle) for the cichlid.
 
Well fed. Corys wont suffer from any nostril, barbels or mouth erosion with any substrate. I had many zebras (CW111) in a 5 gallons with standard pebbles with no problems in the past. They can control their barbels and avoid to hurt themselves.

1-s2.0-S2589514122000895-gr1.jpg


If you're a maniac you can tumble the gravel / pebbles with sand until good smoothness and rinse forever. But I never done that. (I'm a maniac and sand wears impellers, so I wont use it). I only provide a large smooth rock in the front of the tank facing current and sufficient food to make them a little lazy. The rest of the tank was / will be planted as much as possible and provide hiding areas.

To make sure they eat enough, twice a week I stop filtration, wait until water movement stops, Feed top dwellers to keep them occupied. Then I give them a mix frozen brine shrimp and bloodworms with a dropper fixed at the end of long tweezers right on the floor of their smooth rock. Wait half an hour and restart filtration.

Seeing such a small fish sucking up super long bloodworms like spaghetti always makes me laugh.

Just sarted back after 15 years off... I'm Hoping to be able to have something like that again in the near future.
 
Last edited:
Well fed. Corys wont suffer from any nostril, barbels or mouth erosion with any substrate. I had many zebras (CW111) in a 5 gallons with standard pebbles with no problems in the past. They can control their barbels and avoid to hurt themselves.

1-s2.0-S2589514122000895-gr1.jpg


If you're a maniac you can tumble the gravel / pebbles with sand until good smoothness and rinse forever. But I never done that. (I'm a maniac and sand wears impellers, so I wont use it). I only provide a large smooth rock in the front of the tank facing current and sufficient food to make them a little lazy. The rest of the tank was / will be planted as much as possible and provide hiding areas.

To make sure they eat enough, twice a week I stop filtration, wait until water movement stops, Feed top dwellers to keep them occupied. Then I give them a mix frozen brine shrimp and bloodworms with a dropper fixed at the end of long tweezers right on the floor of their smooth rock. wait half an hour and restart filtration.

Seeing such a small fish sucking up super long bloodworms like spaghetti always makes me laugh.

Just sarted back after 15 years off... I'm Hoping to be able to have something like that again in the near future.
Lol, currently I'm watching the little guy attack a homemade gel food I made him, tail up and nose down--whenever I drop his food in (I typically feed small amounts of various pellets or wafers several times a week), you can see his barbels start twitching within seconds, even if the food is dropped on the other side of the tank.
 
Loll, oh yes they where aware of that...

At the moment the filter was stopping, they would all get out of their hideout, knowing party time was coming...

It's Also a good time to check them closely for any problem and try to count them....
 
Also for bottom dwellers that like to sneak around and find their food, You can soak any kind of bottom feeder pellets for a while and add them in the filter output 1/2 hour before light comes on. This will ensure that enough reaches the bottom, I also momentarily cut the filter at some point in that process to make sure that most of it ends on the bottom not in the filter. Then your Corys are good to have fun for 2 days wandering around.

You can easily bring everyone in place, by giving them distinct, as much as possible reliable, calm and permanent kind of feeding area.

I realized how I was overfeeding, when I was able to feed them to the mouth with my hands.

But yeah, at one point it becomes a lot more than just sprinkling flakes on the top.
 
Hmm, you have a love of extreme softwater fish, and you have very hard water. Right away, the poll choices boil down to who you are, and only you know that here. If you are meticulous, will get the RO mix right every week for a water change and are the type who sticks with things, then the Parosphromenus and wild bettas, the Rasbora, the Badis - perfect. If you are a bit less engaged, hastatus. If you tend to wander off or lose interest, a solo Betta splendens is the hardiest of the lot, though shrimp seem to adapt as well.

Your poll would have me voting for killies, because that's what I do. But that's me, so all the poll says is what's popular.
 
I have three pairs of clown killifish in a slightly larger tank, 56x25x36 and they work well but sometimes the male will chase a female or female another female all over the whole lenght. I would not have a problem with a trio in your 25 liters, dense plants, LOW flow and a cover glass. No need for a heater.
Or a small shoal of 10 of some of the boraras, but stay away from the microdevario, they are not small tank suitable at all! I just got a shoal of the least rasbora recently for a 40x40x40 cube and they are so much fun! Wont be the best color, but will be fun hunters.
For a 25 liters I always say a single betta is the best option, loads of color, loads of personality
 
After a more thorough scouring of the list, it hit me that you're right: most of the fish (and even most Caridina shrimp) are all soft-water lovers. I hardly noticed that my entire list had a bias towards softwater vs hardwater. I personally think that I'd be up for the challenge--while none of the above species are particularly "sensitive" or "delicate" fish, all have specific care requirements that will need a good amount of effort.
Hmm, you have a love of extreme softwater fish, and you have very hard water. Right away, the poll choices boil down to who you are, and only you know that here. If you are meticulous, will get the RO mix right every week for a water change and are the type who sticks with things, then the Parosphromenus and wild bettas, the Rasbora, the Badis - perfect. If you are a bit less engaged, hastatus. If you tend to wander off or lose interest, a solo Betta splendens is the hardiest of the lot, though shrimp seem to adapt as well.

Your poll would have me voting for killies, because that's what I do. But that's me, so all the poll says is what's popular.
I definitely referred back to a previous thread when looking at which killi species to include--very informative! It's clear that you definitely know what you're talking about when it comes to killi care.
 
Or a small shoal of 10 of some of the boraras, but stay away from the microdevario, they are not small tank suitable at all! I just got a shoal of the least rasbora recently for a 40x40x40 cube and they are so much fun! Wont be the best color, but will be fun hunters.
For a 25 liters I always say a single betta is the best option, loads of color, loads of personality
If I may, what is wrong with the Microdevario in comparison to the Boraras? While they around the same size, is it a activity level or behavioral difference? I apologize in advance this is something that is relatively obvious, so far I have been getting most of my information from SeriouslyFish.

I have kept several Betta splendens over the years, and have to say--I really do enjoy them! With their "personality" (I know many could debate if begging for food counts, but watching a fish's antics really makes you wonder) and beautiful appearance, they definitely will remain a staple in my book!
 
I have Microdevario kubotai in my tank, and the last elderly Boraras urophthamoides died a few weeks ago. The Microdevario are bigger and deeper bodied than B. urophthalmoides and they are a lot more active, using the whole of a 42 x 18 inch tank. I would not like to confine mine to a 25 litre tank.
Seriously Fish recommends a tank at least 60 x 30 cm/2 x 1 foot for Microdevarios.
 
So, the following are fish that I currently am questioning, as I have seen mixed things regarding their care (both on this forum and online). Do you think that the following are unsuitable for a tank this small (25l)?
  • Wild-type Betta (B. imbellis, albimarginata, rubra, etc.)--I've seen some sources stating that some of the smaller species seem to do well in an 18.9l, including this article from TFH Magazine. AqAdvisor also states that (theoretically, of course, as it is an algorithm) one could keep a pair of B. imbellis at 83% stocking...however, I remember a separate thread in which Gary mentioned that they are too active for a tank of that size.
  • Sparkling Gourami (Trichopsis pumila)--Again, hit or miss when it comes to info--in the thread linked above, someone mentioned that they prefer to be in groups, whilst other sources state that a pair is sufficient. While I don't know if they will do well in a tank that small, I'm more concerned on their social requirements.
  • Scarlet Badis (Dario dario)--Some say they need a 38l at very least, whereas others think a small group (1:3 male-female ratio) can even thrive in an 18.9l aquarium. What are the thoughts on that? I understand that a 25l is definitely somewhere between those twp, which makes me curious as to if this is even a thought to consider.
  • Dwarf Puffer (Carinotetraodon travancoricus)--As stated above, one source will say a single puffer needs a 38l, and another will claim it can be kept in as little as an 18.9l. However, all maintain that they need frequent water changes as a result of their messy eating habits. Would it be possible to reduce the amount of water changes needed (which seems to create possible instablity) by adding detritus worms or ramshorn snails? The thought behind that is that you would have detritivores consuming not only puffer-waste (both from foods and poop), but any other non-palatable puffer food sources--algae, detritus, and dead/dying plant material. In turn, they would also provide a food source for the puffer in question (and likely clean up after it, as well). Is this something that could work out? Or is it better to just skip the puffer in the first place?
 

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