Dupla Ground colour Mountain Grey 3-4 mm, 5 kg

Coloured gravel for the freshwater aquarium. Mountain Grey is grey, grain size 3-4 mm, pack 5 kg.

A coarse grain: food scraps and dirt fall between the grains, so the bed has to be vacuumed regularly. In return water circulates freely through a coarse bed, which is an advantage if the tank has a substrate heating cable. Sand-sifting fish cannot work this grain size.

Colour and safety: the gravel is surface-coloured. The manufacturer states it is pH neutral and resistant to both CO₂ fertilisation and medication, and that it releases no pollutants into the water. The coating meets the requirements of the toy standard DIN EN 71 part 3 (migration of heavy metals) and the batch has been toxicity tested (SNAS reg. 038/S-025, test 16/08370).

How much is needed: the manufacturer's formula is tank length (cm) × width (cm) ÷ 140 = kilos for a five centimetre layer. This 5 kg pack therefore covers about 700 cm² of floor area at 5 cm. For example, a 5 cm layer in a 100 × 40 cm tank takes about 28.6 kg.

Setting up: rinse with cold water before use – transport creates fine dust that would otherwise cloud the water. The recommended layer is 5–8 cm depending on the planting.

Use at normal aquarium temperature only. For plants the manufacturer recommends a nutrient layer underneath (Dupla Depot Mix active).

Documents

• Cleaning and safety notes
• GPSR confirmation (signed)
• Dupla Ground Colour