Contaminated Bacterial Mat Riddles – a type of puzzles introduced in Genshin Impact with version 4.2. Some of them can be encountered in the open world, while others are encountered during the course of story and world quests.

Essentially, slime puzzles are not difficult, and there aren't many of them in the open world. In this guide, we will break down the mechanics of the contaminated bacterial mat so you can solve all the puzzles you come across in Erinnyes Forest and the Mort Region.

Contaminated Bacterial Mat: How to Cleanse

Contaminated Bacterial Mat – a green or purple mass that obstructs passage to underwater or terrestrial spaces.

Green masses are located on bodies of water, while purple ones are on land. There may be several small ones around a large mass. You need to cleanse them sequentially to get rid of all the contamination.

How to Use Xenochromatic Ball Octopus Ability

The Xenochromatic Ball Octopus ability is the main way to get rid of the slime. To activate the ability, interact with the xenochromatic ball octopus underwater or with a pillar on land, where the octopus's power is stored. It looks like a small pedestal with a ball-shaped blue energy mass.

To remove underwater contamination, simply press the left mouse button (LMB). The character will shoot the ability at the mass and destroy it.

On the surface, hold the elemental skill button – E and aim the ability at the mass. The slime will have a health bar – wait for it to drop to zero. Only then will the mass disappear.

In some puzzles, you need to act quickly. If you don't remove several masses with an interval of a few seconds, they will reappear, and you'll have to start over. Keep this in mind during your playthrough.

That's it, nothing complicated. The most challenging aspect you might encounter is dealing with constantly moving masses in bodies of water that need to be cleansed one after another as quickly as possible. For this, the elemental skill of Fischl (Furina) is extremely helpful, allowing you to move freely on water.