Fish Aquarium Tank: Choosing the Size, Glass and Setup for Your Home

The DIVERSA range spans aquariums between 12 and 300 litres, which means the largest model holds twenty-five times more water than the smallest. That difference affects the fish you can keep, the furniture the tank needs and the space it will take up in the room.

What you'll learn from this article

• Which tank volume suits which kind of fishkeeping?
• How does glass thickness change across tank sizes?
• Should you buy the tank on its own or as part of a set?
• How do cold-water and tropical fish affect the choice of tank?
• How should you prepare the room before delivery?

A fish aquarium tank is a watertight glass container that holds water, plants, decor and fish, usually supported by a stand or cabinet. The right tank depends on three factors: the space available, the fish you plan to keep and the time you can give to maintenance. Our DIVERSA glass aquariums come in ten capacities, all made from Guardian float glass.

Ten tank sizes and what each volume suits

The smallest DIVERSA tanks hold 12 and 25 litres. These suit a single betta, a few shrimp or a small group of nano fish, provided the water is changed regularly. They also fit on a sturdy desk or sideboard, so they need no dedicated furniture.

Mid-sized tanks of 45 and 54 litres give room for a small community of fish. The 54-litre model measures 60×30×30 cm, a footprint that suits a bedroom, an office or a narrow alcove. At this size, water conditions are still relatively sensitive, so the stocking level needs some care.

The 112-litre aquarium, measuring 80×35×40 cm, is a common choice for a first living room tank. Larger volumes keep temperature and water quality more stable, because changes are spread across more water. Above that, the 160, 200, 240, 250 and 300-litre tanks suit larger shoals, bigger species or detailed planted layouts.

Glass thickness across the DIVERSA range

Water pressure on the glass grows with the height and length of the tank. Thicker panes are therefore used as the volume increases. According to the product specifications, the 12 and 25-litre tanks use 3 mm glass, while the 45 and 54-litre models use 4 mm.

The 160-litre aquarium uses 6 mm glass. In the largest models, from 200 to 300 litres, the panes reach 8 mm of Guardian float glass. Float glass has an even thickness and a flat surface, so the fish appear without distortion from any viewing angle.

Most of our tanks arrive with a free protection mat as well. Placed under the base, it spreads the weight evenly and evens out small irregularities in the surface below.

Tank on its own or as part of a set

Buying the tank alone makes sense when you already own a suitable stand, lid or lighting. You then choose only the volume and footprint that match your existing equipment. However, the furniture beneath must match the base of the new tank exactly.

For a new setup, a set removes the need to cross-check dimensions. Our shop offers several configurations, including aquariums with an LED lid, tanks with an open stand, and Comfort Sets with a closed cabinet. The most complete option, the Comfort Set with Lid, combines the tank, LED lid, cabinet and protection mat.

Every element in a set is sized to the others. As a result, the lid rests securely on the glass and the cabinet supports the whole base of the tank.

Cold-water or tropical: how the choice affects the tank

Cold-water fish, such as goldfish, live at room temperature and need no heater. Goldfish grow large and produce a lot of waste, however, so they need a generous volume and strong filtration. A small tank quickly becomes unsuitable as they grow.

Tropical fish need water kept at a steady temperature, often around 24–26 °C for common community species. This requires a heater, and a lid helps by reducing heat loss through evaporation. The heater and filter are chosen separately, according to the volume of the tank you select.

The tank itself is the same in both cases. The difference lies in the equipment, the fish and the volume that suits them.

Preparing the room before the tank arrives

Choose the location before ordering, since moving a filled aquarium is not possible. The spot should be level, close to a power socket and away from radiators and direct sunlight. Both heat sources raise the water temperature and encourage algae growth.

Large tanks are heavy once filled, because every litre of water weighs about a kilogram. A 240-litre aquarium with glass, substrate and decor can therefore weigh well over 250 kg. In houses with suspended timber floors, a position near a load-bearing wall usually gives firmer support.

Under our delivery terms, all deliveries are free. Tanks up to 54 litres travel on a next-day service for orders placed before 3 pm, while larger aquariums go out with our own drivers within 14 days, mostly at weekends. For offices, schools or retailers, we also handle bulk orders.

Frequently asked questions

What size fish tank should a beginner buy?

A tank of around 100 litres is a good starting point for most beginners. Larger volumes keep conditions more stable, so small mistakes have a smaller effect on the fish.

How thick is the glass in a DIVERSA aquarium?

Thickness depends on size, rising from 3 mm in the 12 and 25-litre tanks to 8 mm in the 200 to 300-litre models. All DIVERSA tanks use Guardian float glass.

Does a fish tank need a stand?

Small tanks of 12 or 25 litres can stand on sturdy furniture. Larger tanks need a stand or cabinet that matches their base and can carry the full weight of the water.

Can I keep goldfish in a small aquarium?

Goldfish grow large and produce a lot of waste, so they need a generous volume. A small tank may suit them only briefly before they outgrow it.

Is delivery included when ordering an aquarium from MB Store?

Yes, delivery is free. Small tanks arrive on a next-day service, while larger ones are delivered by our own drivers within 14 days, mostly at weekends.