Electrolizer seltzer test Perrier vs. San Pellegrino, what is the black stuff?

We tried testing tap water and seltzer and they all have this black stuff. The only water without the black stuff so far is distilled water, view our test here Tap water test Cote St Luc, Montreal.... . Electrolysis of water is the decomposition of water (H2O) into oxygen (O2) and hydrogen gas (H2) due to an electric current being passed through the water.

Electrolizer seltzer test Perrier vs. San Pellegrino

Water color meaning after using water electrolyzer:

Green: Arsenic, chloroform,Four methyl chloride, copper oxide, ferrous iron

Blue: Bacteria, viruses, organophosphorus (chemical fertilizers, detergents, and pesticides), aluminium sulphate

Red: Price of mercury, ferric iron

White: Lead, zinc, mercury, asbestos, calcium and magnesium

Black: Heavy metals (zinc, lead, mercury, copper, chromium, manganese, cadmium)

yellow: Dissolved oxygen, trace elements, organic minerals

N A Y A vs. Distilled, Demineralized water Electrolyzer test; Montreal
N A Y A vs. Distilled, Demineralized ...