20 Gallon Glowlight Tetra Tank

[Austin Burgess]

Also, would dark substrate be preferred to play sand?

 

[Byron]

For the black water look, is using real leaves preferred to fake? I know some professional aquascapers had almond tea to the water in water changes but that seems above my head. What about real vs fake wood?

There are two things to keep in mind. "Blackwater" as the term is generally used in the hobby tends to refer to the very dark tea-colour tinted water, but the parameters of the water are also part of a "blackwater" fish setup. I do nothing to tint the water, but my parameters are identical to blackwater streams, zero GH and KH, and a pH that is so low I cannot even measure it with our aquarium tests because they do not go below 6 (I had a Tetra ppH test that went down to five, and my tanks were at least that low but more likely from the colour even lower).

Organics cause blackwater. The water in such areas of the tropics does not usually (there are always exceptions) come into contact with mineralized rock so the GH and KH are basically zero. But such areas are also full of organic matter; the wood and leaves that are continually decomposing cause CO2 and CO2 creates carbonic acid which lowers the pH. With no GH/KH to buffer this, the pH can become very acidic. A pH of 4-5, and in some waterways in the 3's, is normal. The presence of all these organics in a watercourse that might come into contact with calcareous rock would result in similarly-stained water but with some dissolved mineral content and a higher pH.

Organics are continually accumulating in any aquarium with fish; all the food they eat ends up as organic matter, and various species of bacteria in the substrate (primarily) break this down, producing CO2 and ammonia. Plants readily take this up, which is one reason why even floating plants are so beneficial. This however does not tint the water much, at least it never has in my tanks. Adding dried leaves, wood, and/or peat will add tannins. Wood is usually pretty slow at this and over time you would not likely see much tinting unless you had a tank full of wood, but even then it is not usually much, given that regular substantial partial water changes will remove much of it anyway. Peat is frowned upon these days because it is destroying natural ecosystems, and there are better and more responsible methods. Such as dried leaves. So long as we have trees we will always have dead leaves. I use oak leaves collected from my former back garden; I moved last year but I have a box of plastic bags full of dried leaves that I collected by the hundreds every autumn. I have had my 10g tank turn quite a nice tint of chestnut brown when I used to stuff it with dried oak leaves for the spawning pygmy cories to feed on, and I grew out some Farlowella vitatta fry in this tank. Decomposing leaves are a rich source of infusoria, the ultimate first food for any fry--another advantage of real over fake.

Fake leaves may give you the look but obviously not the bacterial benefits nor the tinting. And the bacterial properties of dried leaves is very beneficial. Some aquarists do add various teas, but I tend to prefer the appearance as much as the results, and nothing is more natural that a substrate littered with bits of wood and layers of dried leaves.

 

[Austin Burgess]

There are two things to keep in mind. "Blackwater" as the term is generally used in the hobby tends to refer to the very dark tea-colour tinted water, but the parameters of the water are also part of a "blackwater" fish setup. I do nothing to tint the water, but my parameters are identical to blackwater streams, zero GH and KH, and a pH that is so low I cannot even measure it with our aquarium tests because they do not go below 6 (I had a Tetra ppH test that went down to five, and my tanks were at least that low but more likely from the colour even lower).

Organics cause blackwater. The water in such areas of the tropics does not usually (there are always exceptions) come into contact with mineralized rock so the GH and KH are basically zero. But such areas are also full of organic matter; the wood and leaves that are continually decomposing cause CO2 and CO2 creates carbonic acid which lowers the pH. With no GH/KH to buffer this, the pH can become very acidic. A pH of 4-5, and in some waterways in the 3's, is normal. The presence of all these organics in a watercourse that might come into contact with calcareous rock would result in similarly-stained water but with some dissolved mineral content and a higher pH.

Organics are continually accumulating in any aquarium with fish; all the food they eat ends up as organic matter, and various species of bacteria in the substrate (primarily) break this down, producing CO2 and ammonia. Plants readily take this up, which is one reason why even floating plants are so beneficial. This however does not tint the water much, at least it never has in my tanks. Adding dried leaves, wood, and/or peat will add tannins. Wood is usually pretty slow at this and over time you would not likely see much tinting unless you had a tank full of wood, but even then it is not usually much, given that regular substantial partial water changes will remove much of it anyway. Peat is frowned upon these days because it is destroying natural ecosystems, and there are better and more responsible methods. Such as dried leaves. So long as we have trees we will always have dead leaves. I use oak leaves collected from my former back garden; I moved last year but I have a box of plastic bags full of dried leaves that I collected by the hundreds every autumn. I have had my 10g tank turn quite a nice tint of chestnut brown when I used to stuff it with dried oak leaves for the spawning pygmy cories to feed on, and I grew out some Farlowella vitatta fry in this tank. Decomposing leaves are a rich source of infusoria, the ultimate first food for any fry--another advantage of real over fake.

Fake leaves may give you the look but obviously not the bacterial benefits nor the tinting. And the bacterial properties of dried leaves is very beneficial. Some aquarists do add various teas, but I tend to prefer the appearance as much as the results, and nothing is more natural that a substrate littered with bits of wood and layers of dried leaves.

As it’s almost always the case, then, natural is better than unnatural.
But that begs the question, can wood and leaves added be from the back yard, or from the LFS?

 

[Byron]

Also, would dark substrate be preferred to play sand?

No. The substrate in blackwater rivers is thick with dead leaves and often wood. Under it all the substrate is either river sand or mud, or both. Very few have gravel, but there are some and some where these three may occur. Sand is usually buff-tone. In many streams and creeks with fish like Corydoras adolfoi or C. duplicareus it is easy to see why the basic hue of these fish is also buff; from above they blend in with the sand (the habitat stream of C. duplicareus is open sand with lots of branches) and if the fish are stationery, you really cannot even see them. The black dorso-lateral band looks like a stick, further camouflaging the fish.

I use a dark grey tone mix play sand. The buff tone mix is equally good. Or you can buy true river sand. I had black in my 70g years ago but it did not have the effect I was expecting. The fish did become darker, another means they use to blend in. And this in ityself may or may not be a benefit. Ian Fuller counsels against ever using black with Corydoras, and one must admit that it is certainly not something that occurs in their habitats.

 

[Byron]

But that begs the question, can wood and leaves added be from the back yard, or from the LFS?

I have used both. The Malaysian Driftwood available in some fish stores and onlkine is in my view the ideal wood. It is very dark brown, some pieces almost black, it is heavy so it sinks immediately, and the tannins are initial but not as bad as some wood. And I have never had an issue with this wood, while I have with the lighter woods.

It is not easy to get branches; these tend to be the light blonde wood, some of which is grapewood or spider wood, and there are several reported cases of a toxic fungus. I had this from one such piece of wood, and fortunately spotted it in time to save my fish. I have collected oak branches from my back yard. The squirrels periodically chew through some of the smaller branches and they fall to the ground. I leave them inside for at least a year to fully dry, then I rinse them off (usually outside in rain), then bring them in and use what I want and keep the others in a box. Larger chunks of wood take much longer to dry out, and this is essential. You want all the tree sap to dry out completely so the wood is brittle dead dry. Hardwoods like oak, beech, etc are generally safe as wood (and their dried leaves too) so then all you have to watch out for is the collection site, that it is safe (no chemicals, pesticides, fertilizers, etc).

 

[Austin Burgess]

The help is greatly appreciated!

I thought of another question as well. With the eques pencilfish, I am reading conflicting reports online that they need live food. Is that true in your experience? How would a novice keeper go about that?

 

[Byron]

The help is greatly appreciated!

I thought of another question as well. With the eques pencilfish, I am reading conflicting reports online that they need live food. Is that true in your experience? How would a novice keeper go about that?

This is not necessary. There are very few aquarium fish that may be "live food" essential, but none of the pencilfish species I have kept (I've kept nine Nannostomus species) required live food.

I feed mine Bug Bites (they really go for these), New Life Spectrum optimum flake, Omega One Kelp flake, frozen daphnia, frozen bloodworms. The last two (the fresh frozen, not freeze-dried) are one day a week treats; the rest of the time they get one of the prepared foods mentioned, alternating each day.

Years ago, back in the 1980's, I raised wingless fruit flies for my hatchetfish and pencilfish. It was not difficult, but it is not necessary and I just cannot see the value of all that fuss. The prepared foods are highly nutritious today. My N. eques spawn quite often, depositing eggs one at a time under a plant leaf. Once or twice an egg has escaped being eaten and hatched, and there is some natural live micro foods among the floating plants to sustain the fry until I see them.

 

[Austin Burgess]

Curious, reading up some more on the biotope of glowlights (I’m too far into this now to go back), and they are commonly found alongside Hemigrammus stictus, the Red-base Tetra, and found often on in the flood plains where terrestrial grasses find themselves underwater.
Thoughts on this as a setup in a 20 tall?

 

[Retired Viking]

You could use jungle vale for a back ground plant if that is the way you are thinking of going

 

[Byron]

Curious, reading up some more on the biotope of glowlights (I’m too far into this now to go back), and they are commonly found alongside Hemigrammus stictus, the Red-base Tetra, and found often on in the flood plains where terrestrial grasses find themselves underwater.
Thoughts on this as a setup in a 20 tall?

The species is primarily in tributaries of the Essequibo River, in forested areas. During the wet season the rivers/streams flood the surrounding forest. Flooded forest is another aquascape, but here you obviously need plants. From the photos I have seen, the forest is quite thick.

 

[Austin Burgess]

The species is primarily in tributaries of the Essequibo River, in forested areas. During the wet season the rivers/streams flood the surrounding forest. Flooded forest is another aquascape, but here you obviously need plants. From the photos I have seen, the forest is quite thick.

So glowlights may be from a couple of different biotopes?

 

[utahfish]

Curious, reading up some more on the biotope of glowlights (I’m too far into this now to go back), and they are commonly found alongside Hemigrammus stictus, the Red-base Tetra, and found often on in the flood plains where terrestrial grasses find themselves underwater.
Thoughts on this as a setup in a 20 tall?

While something like jungle Val would be ideal it gets way too big for a 20 gallon tank. Corkscrew Val stays a bit smaller and will give a good grass effect. Not sure how well vals will do in a black water set up as they need bright light and do better in higher ph with higher gh. One could try dwarf hair grass though it requires high light as well. A good low light grass like plant is cryptcorne balenase (spelling) it has thinner leaves though not native to south america. Maybe a thin leafed saggitaria or thin leafed chain sword might do well. Another low light plant one could use in background is a narrow leaf java fern again not native to S america and needs a little calcium as the leaves are harder than alot of other leaves. Not sure what else would work in dark water bio tope as a back ground grass reed type

 

[Retired Viking]

Yes, I am working on a sunken forest biotope in a 30 gallon tall tank. I agree that jungle val gets tall, I would let it bend at the surface.

 

[Colin_T]

Vallis doesn't like soft acid water and struggles in blackwater.

Ambulia and Hygrophila polysperma are better options for blackwater set ups.

 

[Byron]

So glowlights may be from a couple of different biotopes?

Yes and no. The species occurs in certain tributary streams of the Essequibo River. These streams are, so far as I know, in heavily forested areas. The South American rainforest goes through two very different seasons each year; the wet or rain season which lasts roughly six months, and the dry season which is also six months. The rains when they suddenly start are heavy and last for weeks and the water courses rapidly rise and flood the surrounding forest, in places more than 12 feet deep. The fish move into these flooded forests to spawn because food (insects, larvae, worms, fruits, etc) is plentiful, they have lots of cover to protect the eggs/fry, and plenty of space so more will survive.

So you could do a relatively-authentic aquascape replicating the streams (floating plants to replicate the forest canopy cover, no lower plants but dried leaves, branches, wood chunks on sand), or you could do a "flooded forest" aquascape which would have sand, wood (standing chunks can represent tree trunks), branches, dried leaves, and substrate-rooted plants. Floating plants still for shade.

This citation is from Seriously Fish's profile of this species:

If you really want to see it at its best, you could set up a biotope tank. Use a substrate of river sand and add a few driftwood branches (if you can’t find driftwood of the desired shape, common beech is safe to use if thoroughly dried and stripped of bark) and twisted roots. A few handfuls of dried leaves (again beech can be used, or oak leaves are also suitable) would complete the natural feel. Allow the wood and leaves to stain the water the colour of weak tea, removing old leaves and replacing them every few weeks so they don’t rot and foul the water. A small net bag filled with aquarium-safe peat can be added to the filter to aid in the simulation of black water conditions. Use fairly dim lighting. Under these conditions the true beauty of the fish will be revealed.​

Hemigrammus erythrozonus (Glowlight Tetra) — Seriously Fish

www.seriouslyfish.com