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


Freshwater diatomsDiatoms are a type of algae, they often manifest in a freshwater aquarium as brown dust, usually on the glass and rocks, sometimes also on plants. This algae is not uncommon in aquariums which do not have plants or have very few plants (as this one currently does) and is usually associated with ammonia in the water. It should disappear with the addition of more plants and time.

Most diatoms are unicellular, although they can exist as colonies in the shape of filaments or ribbons, fans, zigzags, or stellate colonies. Diatoms are autotrophs within the food chain. A characteristic feature of diatom cells is that they are encased within a unique cell wall made of silica (hydrated silicon dioxide) called a frustule. These frustules show a wide diversity in form, but usually consist of two asymmetrical sides with a split between them, hence the group name. Fossil evidence suggests that they originated during, or before, the early Jurassic Period. Diatom communities are a popular tool for monitoring environmental conditions, past and present, and are commonly used in studies of water quality.

The Bacillariophyceae (diatoms) class was described by Ernst Haeckel in 1878. Haeckel was also responsible for Kunstformen der Natur, a book of lithographic and autotype prints which is now available on Wikimedia Commons.

Drawing of a diatom by Haeckel