Blue Lake

Blue Lake fills a former working of the Nowe Szczęście mine, also known as Neues Glück. It lies at around 635 metres above sea level, higher than Purple Lake. Clear water and submerged vegetation distinguish this stop from the lower, strongly coloured pools. Measurements describing the lake recorded depths of around 8 metres.

The differences go beyond appearance. Research in September 2011 found low mineralisation in Blue Lake and much lower sulphate concentrations than in Purple Lake. No iron ions were detected in the samples. The water was acidic, but its pH was higher than that of the lower pools included in the same study. These are findings from a particular sampling campaign, rather than an unchanging description of every drop of water.

An account of biological research published in 2015 recorded the aquatic moss Drepanocladus aduncus. Along part of the shore it formed dense patches extending from the bottom towards the surface. The former working had also become a habitat for aquatic plants, whose distribution differed from the scattered patches found in neighbouring pools.