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Fresh Water Aquarium Accessories

OK, so now I’m getting into the meat and potatoes of freshwater aquarium fish keeping – figuring out what aquarium accessories I need.

And the paramount consideration – only use aquarium accessories designed specifically for fish tanks and fish keeping. This way I will avoid any contamination or poisoning of the water.

Fish Tanks

Most fresh water fish tanks are made by sticking sheets of glass together using a silicone sealant. This limits the shape of the fish tank somewhat.

However, glass rectangular fish tanks are easy to install and available off-the-shelf in many standard sizes.

Modern fish tanks are also moulded from clear acrylic. This for sure expands the size and shape options but there are practical considerations.

Acrylic fish tanks are also more durable, lighter and very much stronger than similar sized glass fish tanks
Acrylic aquariums are easy to scratch and because of the refractive index of acrylic there may be more distortion of the interior which will distract from the viewing pleasure.

Tall multi-faceted towers are made more for the novelty value and room decoration rather than as a suitable habitat for fresh water fish. These vertical fish tanks provide a small surface area for the all-important oxygenation of the water and allows little lateral movement for the fish. The fish can move up and down but not many fish do that in their natural environment.

Size Matters

I have a conundrum here. I know what fish I want to keep, but I do not have the space to place the fish tank. So do I install the biggest tank I can, and fill it with the fish I want to keep hoping everything will work out OK?

I don’t think so.

I will need to make a compromise on the type and number of fish species I can accommodate in the biggest fish tank I can accommodate.

Some interesting fact:

A large volume of water is easier to keep biologically stabilised than a small volume of water and therefore can accommodate more fish
A large tank is more versatile if I change my mind in the future. A large tank can be compartmentalised by inserting glass dividers
On the other hand water is heavy.
The bigger the fish tank, the heavier the installation will be. So I need to make sure the supporting structure is strong enough. A shelf, a cabinet, a floor standing frame, the floor itself.

One litre of water weighs 1 kgm
One litre is 1,000 cu cm.

In old money:

One cubic foot of water equals 6.23 gallons (UK)
One gallon of water weighs 10 lbs.
So a small fish tank 600mm X 300mm X 300mm. Or, 24 inches X 12 inches X 12 inches weighs approximately 54 kgm or 124 lb

And a large fish tank 1,800 mm X 600mm X 600mm. Or, 6 ft X 2 ft X 2 ft is 12 times the capacity and nearly weighs a staggering 680 kgm or 1,500 lbs

Shape Matters

Deep freshwater fish aquariums look good and fit into many rooms.
However depth is less important than maximising the water surface area for proper oxygenation of the fish tank water.

I don’t have long arms, so a deep fish tank is going to be more difficult to maintain. Keeping the substrate tidy, planting plants and fish tank decorations.

And aquarium accessories, like live plants growing in the bottom substrate will require a huge light on the top to make them grow.
So, a maximum depth of around 40mm to 45 mm seems to be the most practical.

Location Matters

My freshwater fish aquarium needs to be located:

where it is easily visible but away from through traffic to avoid any accidents.
Near an electrical outlet
Not secluded or the fish will become introverts.
In natural light but not direct sunlight.
And at a height where it can be comfortably viewed.
The fish tank needs to be sat on top of 13mm thick styrofoam to take care of any unevenness of the base. And the styrofoam is usually fitted on top of a sheet of 13mm thick marine grade plywood.

Fish Tank Hoods and Cover Glass

The purpose of the hood aquarium accessories is to keep the fish in the tank and to keep foreign matter out of the tank. Modern hoods also contain fluorescent lighting tubes and a controller.

The purpose of the cover glass aquarium accessories is primarily to stop water evaporation. Water will condense on the underside of the glass and drip back into the fish tank.

Some hoods come complete with integrated cover glass but these may be a little inconvenient unless there is some facility to access the fish tank to feed the fish and for the regular partial water changes.

Water Heating

I intend to keep tropical fresh water fish so for sure I will need to maintain the water temperature above the ambient temperature in the middle of a winter’s night when the central heating is off.

And to maintain the temperature within one or two degrees I will need a thermostat as well as a heater.

I could get separate aquarium accessories but seems the most convenient and not so expensive is a combined heater thermostat unit.

And the recommendation is to install two smaller wattage units rather than one large wattage unit. It’s very unlikely that both units will fail at the same time so there will be some form of heating available at all times.

And I should not forget the thermometer.

Thermometer aquarium accessories are cheap so I will buy more than one. And they are also very inaccurate so I will need to check the accuracy against some standard device somehow.

Aquarium Accessories: Filters, Pumps and Filter Media

Filter selection needs to take into account:

Size of tank
Number and fish species
But I need to make sure I don’t instal a pump that is too powerful. Or the fish will be swimming upstream 24/7.

An under gravel filter is a good starting point. If inadequate it can be supplemented by a ‘Hang-on’ filter.

There is also a fine balance between the amount of filter media and the amount of waste generated by the fish.
And if I get it right maybe cheap media like filter floss or foam will be adequate for a ‘Hang-on’ filter.

Water Pump

The water pump is more than a aquarium accessory and is used to move water around the tank and I need to make sure it’s the right flow rate for the size of the aquarium.

Length(in meters) X Width(in meters) X Depth of water(in meters) X 1000 = number of liters of water.

Air Pump

An air pump is essential for adequate oxygenation of the water. Air pumps help with moving the water, limiting algae growth and helping keep the fish in good health.


Filters are used to remove waste from the water so that the water is clean and clear.

Filter Media

Peat or foam is used to remove solid waste and ceramic rings, activated carbon and ‘bio balls’ are used to generate good bacteria to overcome the bad bacteria

Aquarium Accessories: Lighting

Fluorescent lights are the most common type of lighting for freshwater fish aquariums.
Fluorescent lighting systems aquarium accessories include the controller and one or more tubes.
Various tubes are available that emit different colour of light or more technical they emit light of different frequencies.
Probably best to use two tubes. Each tube emitting light of a different frequency so the whole visible light spectrum is covered.

I need to make sure there is enough light to encourage growth of any real plants I include in the tank and to show off my fish and the biotrobe they’re in but not too bright that the fish need shades.

And also remember that some fish naturally live near the surface of the water and expect bright light but others live in the shade, in the rocks beneath the plants and glaring lights can and will damage the eyes of sensitive fish.

Maybe in my freshwater fish tank, if I only add artificial plants, I only need one fluorescent tube the length of the tank. I am told that the fish will swim actively in moderate light and the moderate light will show of the colours of the fish much better.

In the future when I start to grow plants in the tank along with the fish I will need to add additional lighting. So probably the best is to use one long tube the whole length of the tank and another half the size at one end. And I design the habitat so that all plants are at the brightly lit end with shade for the fish when they do venture there.

Test Kits

I will need to test the water hardness, the pH level and the amount of ammonia nitrite and nitrate.
Salt water kits do not work for fresh water so make sure to buy the right kit.

Water Chemistry Adjusters

To be on the safe side let’s also include some chemicals to fine tune the water chemistry.
For freshwater fish aquariums I can use Epsom Salts (magnesium sulphate) and Sodium Bicarbonate.

In the next post I will open the discussion on aquarium decorations.


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