Fish jump.

Some do it as a defence mechanism, some do it for breeding, but regardless of the reasons most fish are very capable of jumping and quite a few are exceptionally good at it. Some species, such as Pangio spp. and Erpetoichthys calabaricus, are even known as escape artists, requiring extremely tight fitting covers for their aquaria. Jumping fish can easily become a problem as the fish can hurt themselves or even manage to escape and die.

In home aquaria, fish most often jump when they are spooked, so the primary point of concern is making sure that the aquarium is located somewhere that the fish are not disturbed. A suitable location would be in a dining room or a relatively quiet lounge, away from the doors, preferably where no one would walk by the aquarium on a regular basis. While most fish jump for the sake of jumping, I have also heard reports of an increase in jumping in waters that contain ammonia and I have had a pleco that took to jumping with age.

Of course, it is also important to discourage the fish from jumping. This can be done by adding floating plants, as fish are usually less inclined to jump through a barrier. Even with floating plants, a cover glass is highly recommended as the plants are no guarantee against jumping.

With all of these precautions, the dangers still remain as a fish can hurt itself if it jumps into a cover glass, so it is best to use all of the above measures in combination.

Most fish can not survive out of the water for long, some species, such as gouramis and certain catfish can because they are able to breath even when out of the water, so it is always worth checking if the fish is still alive if it is found after it has jumped. Chances of survival, as long as it is still alive, are quite high. It is usually recommended that the fish is floated in a shallow contained with increased aeration until it is able to swim and then, transferred back to its aquarium.

I thought it would be wise to mention all of these things as I am now down to 9 Danios because one male jumped around 40 mm up, through the opening for food (approximately 50 by 100 mm) and onto the floor, then made its way approximately 1 metre away from the aquarium, where I found it dry and dead by morning.

Danios settling in

Danios are in

It has been almost a week since the Danios were added, they have settled in well and are relatively bold, but do not seem to appreciate when someone walks quickly across the room (as is expected). They certainly seem to enjoy the piece of wood, spending much of their time swimming through the holes in the base and around the stems, but do come right to the front of the glass when they notice me looking at them. The females are receiving plenty of attention from the males and one is looking considerably more plump now, so they may spawn soon.

The fish found the flow of the filter to be disturbing, so I have attempted to slow it down by wrapping filter wool around the rough sponge and placing more still between the sponge and the bio media. It seems to have helped slightly, but not enough, so I am still thinking about how to slow it down further. The stand building project has come to a bit of a stand still as I am quite lazy, but this has given me an incentive to get it going again because the external filter has a 300 lph rating compared to the 700 lph that came with the aquarium.

The fish are feeding well on frozen Daphnia and Artemia, with a supplement of high-protein granules and generic flakes. The 10 fish eat only tiny amounts, so even the smallest tub of fish food will last for years at this rate. Given that most fish food goes off in a matter of 1-6 months, it makes sense to separate it into smaller containers, freezing or chilling the majority of it until it is needed.

There have not really been any major signs of algae, I am still cleaning off mild signs of diatoms from the glass every couple of weeks, but that is it. Most of the plants are doing well, and I plan to split up one or two of the Cryptocoryne parva bunches into individual plants over the next week.

First maintenance

Diatoms begone!Above is the photo of the aquarium after I finished a full maintenance on the aquarium.

I started by turning off the heater and filter, and scraping all the diatoms off of the front using an expired bank card, followed by the sides and the back, although I must admit that I did not make a particularly good job of the back. I was especially careful to not catch the sand, but I think I still may have caught one or two grains which would have scratched the glass.

Next, I drained out 5-10% of the water into a bucket, syphoning up all the diatoms I scraped from the glass. At this point, I decided to clean the filter. So I took the filter out of the aquarium, which was a bit more difficult than I would expect because of the spray bar. I pulled the filter apart and started cleaning the media in the old aquarium water which I had just drained: chlorine and chloramine will kill the nitrifying bacteria that I have been growing and feeding ammonia to. In the two months that the filter has been running for, it has become covered with sand dust, including the media and the impeller. I gently squeezed the sponge in the water until I could not see any sand left on them, then cleaned the impeller, the plastic casing and rubbed the ceramic media between my hands to remove the fine sand coating which was covering it in places. Rubbing ceramic media against itself is not harmful to the filter because the vast majority of the bacteria will be inside the media. Next, I cleaned all the soft plastic as some of it still had fungus on it. I reassembled the filter and placed it back into the aquarium.

Because my tap water is hard, I have lime scale deposits around the top of the glass, inside the aquarium. I cleaned these off with some cotton wool which I soaked in spirit vinegar and then rinsed the areas with aquarium water.

Finally, I syphoned out the remaining water down to about 10 cm from the bottom. So as to not disturb the sand, I then syphoned dechlorinated and temperature matched water back into the aquarium, finishing off with a top up to get the water level right as I do not like the sound of trickling water too much. In total, I changed 36 litres of water.

Finally, I switched the filter and heater back on, managing to spray water out of the aquarium in the process, and added the new piece of wood. The flow of the filter looked much faster, now that it had been cleaned.

Daitoms everywhere

Removing duckweed and adding reflectors

Once duckweed, a very invasive plant, is in the aquarium, it is very difficult to remove it again because even a single leaf is enough for the plant to take over. So, to remove the duckweed, I used fishnets to take as much out as I could, removing the rest of the floating plants in the process. Next, I removed all duckweed which was on the filter inlet and stirred all the plants because some of the duckweed was caught in them. After netting that out, I checked all the sides, under the stress bars, around the cables and tubing, then netted out all which I found. After about an hour or so, I couldn’t spot any more leaves floating around, so I rinsed the duckweed off of the floating plants I wanted to keep and put them back into the aquarium. The Riccia was quite difficult to separate, so I added some from a different aquarium.

Since I already had the lid completely off for removing the duckweed, I decided to add a reflector to the lights. I used super glue to attach some kitchen foil to the underside of the lid, which resulted in the aquarium looking twice as bright as it did before the reflector.

Filter media

Filter media

Before I added the filter to the aquarium, I removed the activated carbon and replaced it with some porous ceramic media.

I used Substrat Pro by Eheim as the space available was quite small at approximately 6 by 3 by 3 cm and Substrat packs more densely than porous ceramic “noodles” would. I do use a number of different types of ceramic media in my larger filters and can not say that one is any better than the other. There is one point to watch out for when buying ceramic media and that is that some media is not porous: this type of ceramic media is actually intended for spreading the flow of water in external filters before it reaches the porous bio-media, not as purely biological filtration.

The carbon I have removed is now put aside, into a dark, cool storage space, until I will need it to remove the remainders of medication which was used in the aquarium. Even though I do not expect to have problems with the fish, I still keep medication for occasions when a couple of fish may have a pecking order dispute or one may scratch itself on a piece of decor. These are rare occurrences, but impossible to prevent.

There is little sense in using chemical media such as carbon or zeolite on a regular basis because these will mask problems in aquaria and can affect the effectiveness of the filter. I even go so far as to not use any chemical media except carbon, and that only on very rare occasions and only because manufacturers seem to insist on including it with every new filter that I buy. I believe that carbon will be used up in anywhere from few hours up to a few days after being added, and there is consensus between many fishkeepers that at most it would last one week. When it is used, carbon is most effective if the water is filtered through it at a slow rate, which is relatively unusual for an aquarium filter as most fishkeepers aim to have the highest flow rate filter possible.

My preferred filter configuration for most aquaria is rough sponge pre-filter, leading to bio-media and finally passing through a filter wool polishing filter. In this setup, the rough sponge should filter out large pieces of solid waste, the bio-media will deal with ammonia and nitrite, and the filter wool (which is also known as filter floss) will “polish” the water, removing any remaining solid waste. The Powerbio is a two compartment filter: the media housing has a large, rough sponge which is accessible through the bottom and a separate, plastic compartment which is accessible through the top of the media housing. I may add a layer of filter wool later on, but for now, I have settled on the rough sponge with the bio-media.

The lighting

Lighting is just as important for fish as for most other animals. This means that fish should have appropriate light, of appropriate intensity for an appropriate amount of time.

The most common method of measuring light in an aquarium is by adding up total wattage of bulbs used and dividing that by the volume of the water, in US gallons. The 1-2 wpg rule of thumb was based on the old T12 lights. Now, the thinner and more efficient T5 and T8 fluorescent tubes are used for most home aquairia. So for modern fluorescent lights in aquariums under 60 cm tall, around 1 wpg is best for the average, undemanding plants, combined with average water changes and average stocking, although it is not uncommon to find anything from 0.5 wpg, in low-plant aquariums, up to 2 wpg, in “high-tech” (meaning fertiliser and CO2 addition to encourage plant growth and prevent algae). I find that generic tri-phosphor fluorescent tubes work just as well as “aquarium” tubes, even for plants, so I will normally buy those to replace old tubes over planted aquaria and I use old tubes from planted aquaria in plant-free setups until the tubes break.

LED lights are also increasing in popularity now and compact fluorescent bulbs are a popular choice for DIY units.

There are few problems associated with low light, with the exception of poor plant growth. On the other hand, high levels of light, long photoperiods, multiple lighting periods per day and photoperiods of varying length encourage algae growth, which can become a long term problem. A timer and a photoperiod of 6-10 hours per day usually go a long way to preventing potential problems. Another point to consider is that some fish require light to be not too bright, or they will feel uncomfortable. In these cases, it is best to provide floating plants, which will cut down on the amount of light entering the water and will give the fish places to hide, thus making them feel more comfortable.

I normally use mechanical timers because they are reliable enough and cheaper than digital timers, but this time, I found a digital timer which was only 2 EUR more than a small mechanical timer with half hour intervals and half the size of a mechanical timers with quarter hour intervals, so it was an easy decision.

The light which was included in the set came is a 24 watt compact fluorescent (also known as a power compact) bulb, referred to as “Plant Pro” by Arcadia. Given that the aquarium will hold about 16 gallons, that gives me approximately 1.5 wpg. It is more than I’m used to, but I have occasionally had success with that much light without addition of fertiliser and CO2.

The heater

Since this will be a tropical aquarium, it will require heating.

Fish are poikilotherms, so (in rather crude terms), their environment affects their metabolism. Because fish are not able to regulate their own body temperature, the temperature of the water will affect their enzyme activity, so it is important that an appropriate water temperature, which is sustainable in the long term, is chosen for the fish to live in. This also means that temperature will affect the lifespan and activity level of the fish: for the same fish, a higher water temperature would mean more active fish with shorter life span, while a lower temperature would result in lower level of activity, but with a longer lifespan.

Changes in temperature throughout the year or during a rainy season can also be a breeding trigger for some species of fish. The latter can easily be simulated by large water changes with cool or cold water. Seasons of the year are more difficult, although still possible by setting the heater to a lower temperature in winter and increasing it toward summer, then lowering it again for the winter.

In fishkeeping, fish are usually divided into three groups:

Fish which live best at water temperatures of 1 – 16 °C, for example, common goldfish
15 – 22°C, fish such as fancy goldfish, white cloud mountain minnows and hillstream loaches
20 – 30 °C, which include some of the most popular aquarium fish, such as neon tetras and angels

There are, of course, plenty of fish which overlap two (or all) of these groups, or are even outside those temperature ranges altogether. Since there are almost no species of fish, available within the aquarium trade in Europe, which fit into either of the first two categories and a 60 litre aquarium, I have settled on tropical fish.

In an average European household, approximately 1 watt of heater per litre of aquarium water (rounded up, as needed) is enough to keep the water up to temperature when the temperature drops inside the house in winter. Because this is a small aquarium, I will be using the 50 W heater which was included in the set. For aquariums over 100 cm in length, I normally prefer to use more than one heater to make sure that the temperature is the same throughout.

Most heaters have inbuilt thermostats, so it should not matter if the chosen heater gives more than 1 watt per litre of water, but when a heater breaks, it is most often in the “on” state, which means that the heater does not switch off when the water is warm enough. Because of this, I prefer to use appropriately rated heaters, so it is more likely that I will have time to notice the problem, before the fish come to harm.

Internal heaters are usually made out of glass (sometimes with a removable plastic cage around them), polymers and metal. The most common heater are made of glass, but these can be cracked easily, so one has to be careful about letting them cool down properly before taking them out of water and large fish can break them. Polymer heaters are considerably more difficult to break, but are slightly more expensive and difficult to manufacture. Metal heaters are uncommon.

Another common problem with internal heaters is that the numbers on the temperature dial (or a separate scale on the heater itself) do not correspond to the temperature that the heater will be heating to, because these can easily become displaced. This is not a problem, as long as you know how high the displacement is.

On top of the standard internal heaters, one can now buy in-line heaters for external filters, external filter with heaters built into them and undergravel heaters.. but all of these are currently less common and none are suitable for the set-up which I am planning.

In addition to the heater, I will also buy a glass thermometer.

The filter

Filters are essential to modern fish keeping: they are home to bacteria which make the water safe for the fish.

The nitrogen cycle in an aquarium commences at the point where fish and dead plant matter produce ammonia. Some of the ammonia is then used up by plants, but the majority is converted, by bacteria which live in the filter, into nitrite. Nitrite is then converted by filter bacteria into nitrate. Some nitrate is used up by plants and the rest is removed during water changes.

The general format of a filter is some sort of pump which causes water to move through some media. This is usually in the form of an internal filter, an external filter, an air pump powered sponge filter, an undergravel filter, a sump, a trickle filter, a hang-on-the-back filter, and so on. For this aquarium, I will be using an internal filter, potentially moving onto an external later on.

There are three types of media usually used in filter:

Mechanical media:
This media includes various sponges, wool and floss, it physically removes dirt from the aquarium by not letting it pass through the filter.
Chemical media:
The primary function of this media is to adsorb undesirable certain molecules out of the water: for example, activated carbon can be used to remove the remainder of medication after a completed treatment. Some “chemical media” works on the basis of ion exchange. It should usually not be used on an every day basis.
Biological media:
Bio-media is the best media for the bacteria to live on because it is usually very porous, so has a high surface area. It is usually made out of some sort of ceramic material. In an undergravel filter, the bio-media is the gravel and in a sponge filter, it is the sponge.

The bacteria are not particularly picky, so will actually live on any surface they can, regardless of the type of media used.

The first step for setting up the aquarium will be cultivating these filter bacteria. They are present in tap water in very small numbers, so I will be feeding them ammonia to encourage the colony to grow. Once the colony is large enough to support fish life, I will be replacing the ammonia with fish (who naturally produce ammonia).


The filter which came with the kit is a Powerbio 700 by Classica (which is the Arcadia brand for non-lighting equipment). It consists of a standard filter power head with a screw-on spray bar attachment, on top of a filter media housing which contains a cage for loose media (containing carbon) and a rough black sponge (not carbon). The carbon has already been taken out and I will be replacing it with some form of bio-media. I will keep the carbon in case I ever need to remove medication after treatments.

The glass box

The aquarium

This log is about a pretty standard 60 litre aquarium (which is approximately 16 US gallons or 13 imperial gallons). It is a standard shape: 60 cm long, by 30 cm deep, by 36 cm high (which is approximately 24 × 12 × 14 inches). For the purpose of setting up and running an aquarium, the specific manufacturer of the glass doesn’t matter.

The three most common materials used for aquaria are glass, plastic and acrylic. I prefer glass because it does not scratch as easily as cheap plastic aquaria and acrylic is used predominantly for oddly shaped or large aquaria.

For simplicity and because I prefer aquariums with a flat front and curved corners, I decided to go for the Arc Tank II kit by Arcadia. It is an all-in-one package which contains most of the equipment needed to start.

The glass is 5 mm thick, with a slight green tinge. The silicone is clear, and the joints are quite neat, so it is barely visible. The surround on the bottom is a thin and made of metallic grey plastic. The aquarium itself is suspended on the frame, about 3 mm from the surface, with all the weight being spread between the four corners. The cover glass is 3 mm acrylic, with a large cut-out for the light fitting on the back a smaller cut-out for feeding on the front. Due to the thinness of the acrylic, it does sag in the centre. The cover glass is quite loose and is very light, so if one is planning to keep fish which are known for attempts to get out, a new cover glass will be required.

Because the aquarium is suspended on a frame, a base mat should not be used. For the same reason, whatever is used for the aquarium stand should provide good support in the corners as it will weigh 70-80 kg when full of water and decor.

Overall, it is nicer than the average aquarium with a lid and looks neat.