Black Venom

Our Black Venom gravel is perfect  for combining with our Black Venom Boulders or to use as a standalone substrate. The dark grey, smooth surfaces of these river stones provide gentle contrast and texture when combined with plants and other hardscape and would look particularly effect when used as detail around plants such as Anubias. They are also ideal for creating ‘stream biotopes’!

Available in 2 & 5kg bags:​

S: Size mix from 8 - 20mm. 

Mix: Size mix from 8 - 40mm. 

L: Size mix from 20 - 40mm. 

*Does not affect water hardness. 

About product line:

WIO Gravels

Please, follow our recommendations to enjoy our gravels:

• Most of our gravels come completely clean. Even though, we recommend to rinse gravels with water before use to remove any remaining dust and to avoid buoyancy of particles on the water fill up.

• You can easily test if a gravel 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.

• Gravels 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.

• We highly recommend you to mix different sizes to create depth in your aquarium. By doing so, it will also look more natural.