Here is what we know:- Water samples came in from the lab today, showing blue green algae (BGA) levels that are low enough to classify as low risk. - The Royal Parks' remote Sonde monitoring device suggests that the BGA in the lake has doubled in the last two days. However, based on the Swim Safety lab results, this would still be in the "low risk" classification.
For perspective, the Serpentine Lido remains closed until the next test results early next week, because of the lake's visual appearance and clumps forming in various spots. At the moment, we have no reason to believe that these clumps are unsafe. The lab are advising that certain green algaes can bloom in very similar ways to blue-green algaes, which may account for the lake visuals at the moment causing concern.
Given the low test results and as the Royal Parks said that they were happy for us to reopen, we have decided to reopen to swimming tomorrow morning.
If you do swim, please be aware that there's still an element of risk, both for humans and furry companions.