Hardiest (NOT expendable) Fish for a Fish-in Cycling?...and foods...and art!

[Bruce Leyland-Jones]

I'm contemplating something new, as I believe I do know what I'm doing (-ish) and have yet to try cycling a tank with fish resident.
It's a standard rectangle of a tank, holding just under 25 gallons after all fixtures and fittings are in place.
The tank will be 'well-planted' from the outset, with plants taken from an established tank, along with matured filter media, moss balls and bogwood.
Substrate will be sand at the front and a plant substrate towards the back of the tank.

I'm aiming for a SE Asian 'feel', with an eventual population of small loach, (possibly Chain), Harlequin and Cherry Barbs, with a trio of small gourami, (Dwarf or Honey, two females to one male). These fish will allegedly be of east European origin.

Water parameters will be;
GH 60mg/L
KH 40mg/L
pH 7.0
Temp: 26℃.

There'll be some nerite snails joining the tank, to assist.
Discounting the loach and, I suspect, the gourami, which do you think might be the safest to employ in the task of cycling? Harlequin or Cherry Barbs?
Please understand that I remain cautious about fish-in cycling, as none of my fish are to be considered 'expendable' and may well bottle it and stick with what I'm familiar with.

Thanks in advance.

 

[Byron]

First thing I'd note is that you are not "cycling" anything here. The live plants which I will assume will be growing since they are from another existing tank will remove any ammonia the fish can provide, along with any ammonia from decomposition in the substrate. I have set up new tanks and added all the fish the same day, because of sufficient live plants, though I do strongly recommend using some floating plants as these are guaranteed "ammonia sinks." The "cycle" will still occur, but provided the plants are sufficient there will never be ammonia or nitrite showing up in tests (using our aquarium test kits), and nitrate may never appear, depending upon the levels of fish/plants and other biological aspects.

What you are really dealing with here, in your thread title question, is established rather than cycled. And some fish do have an easier time in an established tank, as opposed to a new setup. The reason is that while the plants will remove any ammonia and the "cycle" will be a non-issue, there is an instability in other areas involving different bacteria. The water parameters and conditions may fluctuate (pH for example for a few weeks to months, depending) and not all fish have an easy time with this. The smaller the size of the fish species, the more sensitive they are to this instability.

From the fish species mentioned, I would consider the loaches to be the most sensitive. This raises another issue though, being if they are suited to this small a tank. Don't have those all-important dimensions, but the dwarf or chain loaches (Ambastaia sidthimunki) really need a 3-foot (90 cm) length tank minimum. I had a group of this species, and five is minimum, in a 3-foot tank for years. With a sand substrate, lots of chunks of wood...and absolutely no "plant" substrate stuff. These substrates are dangerous for all substrate-level fish for primarily bacterial reasons, in addition to roughness.

 

[itiwhetu]

Cherry Barbs have always been my fish of choice, to start a tank.

 

[Bruce Leyland-Jones]

...and absolutely no "plant" substrate stuff. These substrates are dangerous for all substrate-level fish for primarily bacterial reasons, in addition to roughness.

I'm yet to see hard evidence to support this.
Substrate-dwelling fish generally have enhanced immune systems, to facilitate their lifestyle amongst the grot and as for roughness, I've been amused by the relatively recent assertion that sand is essential for both loaches and corys, for example, to thrive.
I mean...have you seen what they live amongst in the wild?
Granted, aquarium soils are relatively new, but I'm yet to find anything suggesting that they are dangerous to fish in tanks.

If, of course, you can point me in the direction of something to support your points...

 

[Bruce Leyland-Jones]

Cherry Barbs have always been my fish of choice, to start a tank.

My thoughts also...although the Harleys came a close second.

 

[Uberhoust]

I examined my aquarium soil under a microscope, Tropica Aquarium Soil, and found fragments of what looked like pumice or other sharp mineral fragments in the mix. It did seem to have an adverse affect on the two corys I had, but no affect on the blue stream goby who dug extensive caves in the soil. I cannot speak to the biological aspects of the substrate.

 

[Avel1896]

Fish while cycling
Why the heck put fishes at such risks ?

 

[Bruce Leyland-Jones]

Fish while cycling
Why the heck put fishes at such risks ?

It's already cycled...apparently.

 

[itiwhetu]

We have had this discussion about it being cycled, your tank is apparently cycling so it is fine to add fish to it.

 

[Byron]

I mean...have you seen what they live amongst in the wild?

I have, and it is in every species' case sand, or mulm, or dead leaf litter, or a mixture. Ian Fuller is one of the most knowledgeable cory people, he owns/runs CorydorasWorld, and he has collected dozens of cories in South America, and he told me that these are the habitat features, and in an aquarium sand is by far the safest option if one cares about the fish. Cories are also filter feeders, and every video taken of these fish in their habitats shows, so that is not even an argument of merit. The point being, they cannot filter feed gravel. And not one of their habitats has gravel as the sole substrate material, it will be a composite substrate with one of the afore-mentioned materials mixed in.

As for loaches, that is a bit different. Some occur in rivers with sand, some have relatively fine gravel. The suggestion to keep loaches over sand is still a good one, and there are some that definitely will benefit. Well, to be honest, they all will. But here it is for different reasons.

As for aquarium "soils," in addition to their composition (@Uberhoust referenced this aspect) there are significant issues with ammonia, various bacteria, in these mixes. Sand provides a healthier environment, that is without question here. And barbel loss among cories is sometimes due to the sharpness of the material but often a bacterial issue that would not occur with sand.

I will post Ian's short article on substrate in my next post, minus the photos.

 

[Byron]

Corydoradinae Habitat conditions (Ian Fuller)

There are constantly discussions held on social media channels as to the correct substrate for Corydoradinae catfishes. So, I decided to put some of the facts together based on personal observation in many species of Corydoras’s natural habitats.

The first thing to remember with this group of fishes is that they are primarily filter feeders. They do not have cutting or crushing teeth like some of the predatory Catfish, nor do the have rasping teeth like the grazing Loricariid Catfish, these fish will sift the substrate, which in the majority of cases is sand.

Smooth sand which been created over millions of years by the constant tumbling action of moving water, whether it be the oceans tidal and wave actions or the constant varying flow of rivers. The more the flow and tumbling action the finer the sand becomes.

In some areas the sand found can be fairly course, and grains could be as large as one millimetre, or as fine as caster sugar, the one thing that will be common is that the grains will be smooth and not sharp and gritty like quarried sand as use in the building industry.

Over many years I have spent many hours watching, and filming Cory’s feeding, in some cases it is quite comical, especially with the larger straight (Lineage 8) and curved (Lineage 1) snouted species who tend to bury the deepest, Some almost completely burying themselves when they dive right in searching out the food they sense is there. I have taken video clips of the feeding actions of several species from different lineages. And all, even the smallest species will mouth the sand.

Many people argue and state that “Their Cory’s are perfectly happy living over gravel”. But I find it very difficult to see how they can determine the happiness of a fish. They may be surviving and because they are actively scurrying around in their constant hunt for food are seen as being happy.

I have seen video’s on face book showing the presenter displaying a rough irregular gravel they discovered at a particular location and stating that Cory’s are happy living amongst it. However, I know and have collected in that very location many times and the gravel compound that the person in the video is showing is actually part of the aggregate that was used during the construction of the relatively new nearby road bridge.

There are places where there are gravel, pebble and rock rivers and streams, but when taking a good look at some of these places the streams and riverbeds are sand. The natural habitat of C. weitzmani is one such place. I have never seen deep layers of a single sizes gravel; it is always a range of many variable sizes and usually it appears as a widespread scattering.

The biggest problem with using any type of gravel in an aquarium is that food particles will fall between the particles and decompose, and if the aquarium is not maintained and or filtered adequately the water quality will deteriorate very quickly. The other danger as far as keeping Cory’s over gravel is the fact that they cannot easily move gravel to access the particles of food within it, and if the gravel is of anything other than smooth and rounded particles they can and often do damage their delicate barbels and mouths parts.

As I hinted at earlier, different forms and sizes of Cory will feed at different levels in the substrate, from dwarf species working the surface, medium round snouted species delving five or six millimetres into it, and the larger straight and saddle snouted species often burying themselves.

Regarding decoration, naturally there are few plant laden habitats, most are plain sand streams and riverbeds, in swampy areas there may be some vegetation, but there will certainly be lots and lots of leaf litter, tree roots, fallen branches, twigs and vine roots.

 

[itiwhetu]

I'm yet to see hard evidence to support this.
Substrate-dwelling fish generally have enhanced immune systems, to facilitate their lifestyle amongst the grot and as for roughness, I've been amused by the relatively recent assertion that sand is essential for both loaches and corys, for example, to thrive.
I mean...have you seen what they live amongst in the wild?
Granted, aquarium soils are relatively new, but I'm yet to find anything suggesting that they are dangerous to fish in tanks.

If, of course, you can point me in the direction of something to support your points...

I agree with you, I am tied of this "filter feeder" I love sand thing with Cory's. Not fact based and as far as I'm concerned it is rubbish. The biggest threat to Cory's or any catfish is Nitrates, not the substrate they are kept on. I have never used sand in an aquarium and nobody will ever convince me that it is the best substrate for a freshwater tank, fine gravel should be the medium of choice.

 

[itiwhetu]

Corydoradinae Habitat conditions (Ian Fuller)

There are constantly discussions held on social media channels as to the correct substrate for Corydoradinae catfishes. So, I decided to put some of the facts together based on personal observation in many species of Corydoras’s natural habitats.

The first thing to remember with this group of fishes is that they are primarily filter feeders. They do not have cutting or crushing teeth like some of the predatory Catfish, nor do the have rasping teeth like the grazing Loricariid Catfish, these fish will sift the substrate, which in the majority of cases is sand.

Smooth sand which been created over millions of years by the constant tumbling action of moving water, whether it be the oceans tidal and wave actions or the constant varying flow of rivers. The more the flow and tumbling action the finer the sand becomes.

In some areas the sand found can be fairly course, and grains could be as large as one millimetre, or as fine as caster sugar, the one thing that will be common is that the grains will be smooth and not sharp and gritty like quarried sand as use in the building industry.

Over many years I have spent many hours watching, and filming Cory’s feeding, in some cases it is quite comical, especially with the larger straight (Lineage 8) and curved (Lineage 1) snouted species who tend to bury the deepest, Some almost completely burying themselves when they dive right in searching out the food they sense is there. I have taken video clips of the feeding actions of several species from different lineages. And all, even the smallest species will mouth the sand.

Many people argue and state that “Their Cory’s are perfectly happy living over gravel”. But I find it very difficult to see how they can determine the happiness of a fish. They may be surviving and because they are actively scurrying around in their constant hunt for food are seen as being happy.

I have seen video’s on face book showing the presenter displaying a rough irregular gravel they discovered at a particular location and stating that Cory’s are happy living amongst it. However, I know and have collected in that very location many times and the gravel compound that the person in the video is showing is actually part of the aggregate that was used during the construction of the relatively new nearby road bridge.

There are places where there are gravel, pebble and rock rivers and streams, but when taking a good look at some of these places the streams and riverbeds are sand. The natural habitat of C. weitzmani is one such place. I have never seen deep layers of a single sizes gravel; it is always a range of many variable sizes and usually it appears as a widespread scattering.

The biggest problem with using any type of gravel in an aquarium is that food particles will fall between the particles and decompose, and if the aquarium is not maintained and or filtered adequately the water quality will deteriorate very quickly. The other danger as far as keeping Cory’s over gravel is the fact that they cannot easily move gravel to access the particles of food within it, and if the gravel is of anything other than smooth and rounded particles they can and often do damage their delicate barbels and mouths parts.

As I hinted at earlier, different forms and sizes of Cory will feed at different levels in the substrate, from dwarf species working the surface, medium round snouted species delving five or six millimetres into it, and the larger straight and saddle snouted species often burying themselves.

Regarding decoration, naturally there are few plant laden habitats, most are plain sand streams and riverbeds, in swampy areas there may be some vegetation, but there will certainly be lots and lots of leaf litter, tree roots, fallen branches, twigs and vine roots.

The filter feeding thingy. I would like people to consider that what is being said is that Catfish can determine the difference between sand and a piece of food in their mouths. That is the equivalent of us taking a mouthful of peanuts and gravel mixed together and only swallowing the peanuts!!!

 

[Byron]

Here is one of dozens of videos you can find that show exactly how cories eat, by taking up a mouthful of substrate, and expelling the non-food (sand, or whatever substrate material) through the gill slits. This issue is not even questionable, it is a fact of nature. The evidence is clear for all to see, and honestly, to deny this is a fact--well, that is your problem.

 

[itiwhetu]

How do you know he is eating and not just playing with the sand because he can.