McDONALD LAKE NANO BOULDER

71070312

Lake McDonald is Glacier National Park’s biggest lake in Montana, USA. One of the most striking features of this lake is the presence of a variety of coloured rocks and pebbles just below the water surface and on the shores. 

The coloured stones of lake McDonald are entirely the credit of the planet. The colour of the pebbles is due to the iron content in sedimentary pebble rocks and the degree of its oxidation. So, for example, where iron was in close contact with air, red colours prevail there. But green colours are typical for stones formed at great depths, where oxygen is very limited.

Initially, rocks were formed for millions of years and, depending on conditions, acquired those very amazing colours. Subsequently, these lake rocks were ground into small coloured pebbles by giant ice blocks during the Ice Age. Streams of meltwater brought coloured stones into the valley, which was filled with glacial runoffs.

Available in 2kg bags

*Does not affect water hardness. 

NANO BOULDERS

Please, follow our recommendations to enjoy our boulders: 

• Most of our Nano Boulders come completely clean. Even though, we recommend rinsing boulders with water before use to remove any remaining dust.

• You can easily test if a boulder is inert or if it will change slightly the pH and hardness. Simply place few drops of vinegar on the rock. If the vinegar (a base substance) fizzes or foams, it indicates that the gravel contains some calcium.

• Boulders that contain calcium may alter the pH and kH. This can be especially pronounced if you have acidic water or CO2 addition. You can easily control it by regular water changes with osmotic or soft water. You can also use a water softener.