Hello, AKA!

I'm looking to set up a new small live plant tank (20 gallon long is the size that I'm thinking about, since finding 15s these days is tough) and I've been contemplating the right little fish to add.

I have over a decade of fish keeping experience, from the basic betta tank all the way to marine reefkeeping. I have yet to get my hands on any killifish, and I've always wanted to give them a try.

I have several questions to ask of you experts with regards to my initial tank setup, and most-likely-to-succeed fish species. First, I intend to start the tank with RO water, since water quality will be a big factor for live plants, not to mention delicate fish. As such, I have the ability to set and buffer my pH and hardness to whatever would strike a good balance between fish and plants. What are the range of values the most common killie species thrive in?

In a 20 gallon aquarium, how many killies can reasonably be housed? No, I don't want to breed them; I'd prefer species that either are difficult to spawn, or whose eggs require special attention to hatch (since I'm not planning to disrupt the plants to remove them). Is it possible to house just males, or will they fight excessively?

Are there any problems with other tankmates, such as cories, otocinclus or cherry shrimp? Will they remain healthy if the tank has a 4-5 degree temperature drop at night after lights out? I tend to keep daytime temps between 76-78.

Thanks for your time!
Steph

The temperature range yhou mention is a little on the warm side for many killies. Maybe a tank loaded with A australe would fit your bill. They are quite pretty, do well in that temperature range and with a tank of rooted plants and a bunch of hornwort, they will look spectacular. A tank of them with a ton of hornwort is where I first saw killies and they were australe. The shop owner sold australe out of the tank for years and it was a nice self sustaining population. Some pairs will allow fry to grow and other pairs may not. Seems an individual temperment, not a species dependant thing. Another choice might be a small Fundulopanchax like a gardneri. They are more bold and a little more prone to have arguments among males but should be ok in that size tank. Just depends upon if you like "in your face" fish(gardneri) or shy peeking fish like the australe. I always loved the australe in that type enviroment. Stunning when a male just sits still looking at you from some cover. The gardneri have temperments more like maybe tiger barbs and cherry shrimp might not last long. Australe may ignore them though. I would stick with one species of killies though.
I much prefer the appearance of "Chocolate" or wild strains of australe over the so called gold or red-gold but it is personal preference.

I forgot about your question on pH. All over the map but more are good in 6-7 than over 7. A lot of killies do not seem particularly sensitive to pH shock but most species other than Nothobranchius genera do better in slightly acidic water.

Most killies do well in softer water lets say 50 to 150 ppm tds. Hardness for many Aphyosemions like australe is ok under 140 ppm tds but harder is ok for Fundulopanchax like gardneri maybe up to several hundred ppm tds. The water hardness has more of an impact on egg fertility than comfort or survivability among most killies. Besides soft water tending toward acidic and having a higher propensity for pH swings (very little buffering), acidic water helps in avoiding any problems with ammonia.

Thank you very much for your information. It's good to hear that balancing my water chemistry between the plants and fish will be a breeze.

The temperature can be brought down easily enough. In fact, I'm thinking of doing several mosses on driftwood and in the foreground, and they're quite content in the 72-75 degree range. The temperature dropping at night is something I've gotten in the habit of in my plant tanks as I feel it gives them a more natural rest period at night, but if the killies don't mind things a bit cooler I won't worry about it.

Thanks again!
Steph

Welcome to the wonderful, sometimes a little weird world of killifish. :) Please feel free to completely disregard what I'm suggesting here.

Your idea of a variety of similar fishes fueling a planted aquarium is neat. As a sufferer from MTS (Multiple Tank Syndrome, I've had a couple of tanks of odds 'n ends and some nice plants. However those were a mixture of tetras
and extra killies (or killies not deemed proper breeding stock that I just didn't have the will to euthanize.)

"If a fish can fit in the mouth of another, it will." But I was delighted to see how tolerant large Epiplatys were with Characins and Cyprinids that were a little larger than bit-sized.

Male killies, without the presence (pheromones?) of the females are a lot less combative than in a mixed gender aquarium. And the males of a species may respond more assertively to females of their own species. Obviously the males offer the most color and variety. And at a killie meeting mini-auction (See the affiliate clubs above) odd males coming up at the end when people have no more tank space) sell for very little.

Since most killie-nuts (at least say) that they are interested in breeding the killies they have, extra females may be many times even more treasured than pairs or males. That is perfect for the person designing an aquarium or aquatic garden.

However the birth of a fish is also cause for wonder. A 15 or 20-gallon long tank (would that I had the space for a fish-room of those) is not only a great environment for many plants, but a provides a lot of surface and shelter for fry. Whether you would be interested is your call.

Do you start the aquarium with just RO water or a mix? If the latter, what range is most comfortable for your plants? Bill gave a very useful overview of hardness for most plant spawners.

By the way, many killie people are prone to use tanks that are so small that require a lot of care because they are at the minimal end of the safe range for whatever killie species they have. ("Too much good stuff.")

Your interest in 20-longs would make raising killies in a “natural set-up” is "easier" because that space lends itself to producing (remembering your first guppy tank) healthy, faster growing, even more gorgeous youngsters if
they have more space, more hiding places, fewer adults (or larger, hungry siblings), better water quality which often goes with a 20 as opposed to a 5.5 or a 2.5 or even a 10.

Here's a suggestion that you are welcome to make use of or blow off:

Killies that are raised together seem to sort out their pecking order when young. Either there is less damage or we simply don't find the losers. It is probable that at their size, that most can flee aggression and they get used to each other and the status quo.

Ironically when we bag them up separately for a show we can upset the apple cart.

A pair of adult killies, a batch of eggs just hatched or even several youngsters in a tank such as you describe would have room to rumble. They would probably settle down more comfortably that in a smaller aquarium.

There is also a dynamic in a single-species tank of killies (busy procreating) that is absent from many aquariums. With your RO unit, if your australe weren't producing viable eggs (or the more evident fry) you could simply walk down the mineral level for them. Less would need to be done for the gardneri that Bill also recommended.

There are hundreds of other great killies out there. If you have time, stop by Google and image search Aphyosemion, Epiplatys annulatus (the rocket killifish), Scriptaphyosemion, "Chromaphyosemion," "Diapteron," or even
Pachypanchax.

If you like schooling fishes, search for lampeyes or "Aplocheilichthys"

Actually there is only one lampeye species still in Aplocheilichthys, but a lot of the social lampeyes can be found that way. They can be pretty tolerant of fry in the weeds.

One could also look for
Congopanchax
Foerschichthys
Hylopanchax
Lacustricola
Lamprichthys (The mother of all lampeyes from Lake Tankanyika)
Micropanchax
Plataplochilus (rarer)
Pantanodon (brackish-marine)
Poropanchax
Procatopus

If I have missed some, I apologize.

I snuck a look at your residence and I'm dismayed to mention that last week was a wonderful week for killie nuts in your area. (Sounds like some fishing camps, "You shoulda been here last week.") I hope you were there and this ditz just forgot your name.

Thursday was gardneri fest at MAS. The Minnesota Killie Keepers had a wonderful show over the weekend. Great company, neat killies, food (oh my!) and a bunch of male killies that went for $1 each at the end of the auction
Sunday.

Hope something here is useful grist for the mill! ;)
All the best!

I am am old timer who is getting back into keeping a couple of Killiefish species.
I have just begun with a pair of Orange A. australe in a 20L which they share with about 36 Zebra Shrimp.
I have gone bare bottom with Java moss clumped on the bottom and Najas guadelupensis filling in the upper half of the water column. I had some smaller juvenile orange A. australe but they seem to have been taken down by Velvet which has not affected my older pair. I did not want to treat the tank with salt and malachite green because the shrimp are so sensitive to changes and chemicals.

I had a couple pairs of Fundulopanchax scheeli in a 29H which was only 2/3 filled but I still lost one pair due to jumping out the few small openings in the cover. I only have a mass of Hornwort in this bare bottom tank.

All of my pairs were small when i bought them and they are only now beginning to reach the age and size when their fertility should be better and egg productions higher.
I feed them brine shrimp nauplii 2 or 3 times a day so there is always food for any fry that appear. I am trying to use the colony breeding method but I may resort to my more typical practice of segregating the sexes for a few days then bringing them together in a 4.5 gal bare breeding tank furnished with floating and bottom acrylic spawning mops to make sure i have more fish to work with then I hope to use the more laid back colony style method.
These are a couple of my favorite but A. striatum is another highly recommendable species for a species colony breeding set up.

There are many species which may be raised as species colonies and still make lovely display tanks.
I can make up any kind of water i want but the city tap water has been running at a ph of 7.4 and about 125 ppm TDS which is made up of a good balance of carbonate hardness(KH) of about 5 and dGH is also about 5 or 6 degrees so I can count on the ph remaining stable and expect good hatches.
If you use a KH less than 3 degrees the pH tends to drop especially if you don't change the water much. I tend to change about 70% of my water each week so the chemistry is pretty stable. Once I get a good distribution of ages and sizes I plan to stock Cherry Shrimp in the Fp. scheeli tank. I can get a bunch for free from a friend and the small ornamental shrimp do not harm Killiefish eggs or fry.
A certain percent of the young shrimp will make up the occasional snack for the Killies.
I have raised about 100 species of Kilies in the past 40 plus years but I still find that some of the oldies are still among the goodies. I think many of us who have been in the hobby long often revisit old favorites as I am doing.

I raise and sell a lot of expensive L-number Plecos, L134, L260 and L333 and am back at trying to breed wild Blue Discus again and these fish require some serious effort and involve expensive internet fish deals. Revisiting old favorite Kiliefish for fun is therapeutic to me.
I am in a serious attempt to breed a beautiful pair of wild Apistogramma cf. agassizi Netz/Net. If successful they will sell well but sometimes going back to the familiar helps keep this a hobby and not all serious business.