Hey everyone. I've kept fish most of my life, but just recently wanted to give some of these nothos a try. I've been doing research and I've been getting mixed reviews on exactly what ph and hardness they prefer. I've read they prefer slight alkaline water, which makes sense to me. Here is my question to everyone, the water where I live is terrible. I live in west texas where our water source is constantly low and has a high concentration of bad stuff. It is extremely hard and alkaline, with a ph around 8.0 or so. Would I be better off using RO water supplemented with a buffer or sea salts containing trace minerals, or giving my local water source a try? Any advice is appreciated, thanks.

Jake

Jake,

Nothos do prefer water that is alkaline and, in captivity at least, hard water is best. Hard water will have good buffering capacity and avoid rapid drops in pH which can often happen, especially when using peat as a spawning medium.

I would recommend that you try using your tap water just as it is and I suspect it will work well for Nothos. Age it for a few days before using it and, if necessary, add something to neutralize the chlorine or chloramines.

When I lived on the Canadian prairies I had very hard tap water and my Nothos did very well in that. Since I moved to Vancouver Island, where the water is extremely soft (I have on occasions measured TDS at <10 ppm in my tap water) I have to add all sorts of "stuff" to the water to raise the TDS and the buffering capacity. The Nothos do alright in it but not as well as they did when I was using the hard tap water and it is a real nuisence to have treat the water.

Brian Watters

Mr. Watters,

Thank for you the reply, and a quick one! I will give the local tap a shot. I am willing to bet the water chemistry in the Canadian prairie would be similar, as I also live in the prairie, maybe not as treated lol. If you don't mind me asking, though this is a separate questions, where is a good place to purchase notho eggs? I know there are many ebay and other auction for eggs overseas, but I find it a little sketchy. I would rather try and locate a breeder I can talk with. Is my best option to join the AKA, and check the classifieds there? Thanks again

Jake

Brian, Many people recommend adding salt (sodium chloride) to prevent velvet. Is that better or worse than adding calcium and magnesium salts to increase the hardness? It seems to me the buffering is more important than the conductivity provided by sodium salts. I do not keep Nothobranchius species regularly because salt addition seems wrong. But if I don't they do not live very long.

Lee Harper
Media, PA

Jake,

As you say, there are quite a few differenr sources of killifish eggs but joining the AKA is always a good way to start. You would have access to the AKA's fish and Egg listings (F&EL) in the BNL and being a member is a good basis for establishing personal contacts that might also be another way to acquire fish and/or eggs and to learn about killifish. Similarly, if you are in an area where it is possible to join one of the AKA affiliate clubs that is another good way to develop contacts. Any sales through the AKA's F&EL are subject to the Code of Ethics so the risks of getting a bad deal are minimized.

Brian

Lee,

I am not sure that I can give you a definitive answer to your question but I can simply relate my personal experiences.

When I was keeping Nothos in Regina, Saskatchewan, where the water was very hard and alkaline, I had no need to add any buffers to the water as it remained alkaline no matter what. I did, however, get the odd incidence of velvet, especially in certain species of Nothos. One example that springs to mind is N. flammicomantis. I very rarely was able to keep a batch of this species without them getting velvet at some stage, in spite of regular water changes and not crowding them. I routinely added salt to the water and that helped somewhat but did not eliminate the problem.

Here, on Vancouver Island, where the water is very soft and to which I add "Equilibrium" and buffers, as well as salt (although less than half the dosage that I used in Regina) I have yet to see a case of Velvet after 7 years. And that includes in that time about 6 generations of N. flammicomantis, the species that gave me so much trouble in that regard in Regina.

So, at both locations, the water was/is well buffered but at one I got the odd case of Velvet, at the other not.

Brian

Brian,
Thanks for your detailed response. It seems that some water is more susceptible to allowing velvet to thrive than other water. The difference is not necessarily easily explained. On the other hand don't many Nothobranchius species thrive in relatively sift water in nature? Is the unique clay perhaps an important contributor to their success? Could the ion exchange capability of clay have some effect? Have you looked at clays as components of Nothobranchius husbandry? Many questions, I am looking for many answers.

Lee Harper
Media, PA

Lee,

You are correct in saying that the natural habitats for most Nothos have relatively soft water. However, it is also mostly alkaline and that is due to the buffering capacity of the substrate clays which are alkaline. The combination of soft water and alkaline conditions is something that is practically impossible to achieve in the confines of our small aqauria, hence the need to add buffers if the tap water is soft. These are topics that I discussed in some detail in my JAKA article on the ecology of Nothobranchius and there are data presented therein regarding the water conditions measured at a few hundred localities.

The substrate is absolutely critical in maintaining the water conditions that one typically sees in Notho habitats. The only Notho pools that one encounters in nature that have acidic water are those in which there is a significant amount of decaying vegetation and where, presumably, the buffering capacity of the substrate is somewhat overwhelmed by products of the decaying process.

I have never experimented with clay as a substrate in captivity but, by coincidence, only last week, while purchasing pond supplies at a local garden center, I noticed some containers of "Koi clay" for sale and purchased one to experiment with. Koi clay is, basically, montmorillonite clay (a swelling clay with a high ion exchange capcity) and one which is prominent in the substrate of Notho habitats. I am quite sure that it will not be a practical substrate for use in aquaria, at least not for general use, as it will be stirred up by the fish and I suspect that the tank water will be constantly very murky (as, in fact, most natural habitats are). I still feel that peat moss is the most practical medium for us, as hobbyists, to use.

Nevertheless, I will experiment with the clay, one of my main interests being in seeing how it works as a storage medium for the eggs during incubation. However, even in that regard it is impossible to simulate nature because of the vast differences in the volumes involved and the fact that in nature the substrate is part of a vast system that includes the deeper soil layers from which moisture can be drawn up into the near-surface layers. This is the sort of experiment that could take months or even years before any useful information comes from it and, if anything does, I will report on it here and/or in JAKA.

Brian Watters

Brian,
A few additional thought/speculations about the clay substrate. I have experimented a little with greensand which is also a clay containing material. It does cloud the water but eventually it clears, especially in the presence of Java Moss. It does seem, in my limited experience, to reduce the infection of Nothobranchius species by velvet. But I have not tried it without adding some salt.It adds potassium and iron to the system which may or may not be beneficial. I am surprised that the natural habitats are perpetually cloudy. I, of course, have never been there, but I have collected in many USA states and in Peru and Uruguay. Every still water pond has been perfectly clear until disturbed by cattle or fisherman. The only cloudy water I have encountered is in the fast flowing tributaries of the Amazon, which are always clouded. Even the back waters an rivulets adjacent to the Amazon are perfectly clear. I have seen clouds of infusoria next to cattle droppings in pasture pools in Uruguay. Austrolebias fry loving that food source.
The greensand makes a convenient way to collect and isolate Nothobranchous eggs due to the size difference. Of course, every time you collect eggs, it takes a couple days for the water to clear. The fish don't seem to care and neither do I.

Lee Harper
Media, PA

Lee,

Many years ago, I did try green sand but gave up on it because of the constantly cloudy water and it did not eliminate the need to get the eggs into something like damp peat moss for incubation. I found it easier to let the fish spawn into peat moss and then simply squeeze the excess moisture out of that and store it for incubation without the nuisence step of separating the eggs from the green sand.

Green sand can contain smectite type clay minerals but one of the major components is a mineral called Glauconite which is a mica, and not strictly a clay mineral. Glauconite is also a layered silicate mineral, as are clays, but has quite different moisture retention and ion exchange properties to a true swelling clay such as montmorillonite.

When using green sand there is still the necessity to store the eggs in some other moisture retentive medium, such as peat moss, for incubation of the eggs. With a purely montmorillonitic medium it should be possible to store the eggs for incubation directly in the clay medium. In nature the clay substrate provides some moisture (from mineral interlayer sources) during the dry season and that keeps the eggs viable. As I mentioned in my previous message, one of the problems with using clay in our fishrooms is the small volumes of the medium that one is forced to use, compared to the natural systems. If left exposed, a small volume of clay will still become profoundly dry in spite of with the interlayer moisture properties so I would anticipate that if, for example, one used Koi clay as a spawning /storage medium it would still have to be stored in a sealed but slightly permeable container (e.g. a plastic bag) once it reached a certain state of "dryness". This is what I want to experiment with.

Brian