Dear Richard, Most likely ...
Published by Bruno Peeters, managing director at Model Engineering
Dear Richard,
Most likely this green color and the turbidity are caused by (micro)algae. You can check this with a simple microscope.
If so, then this indicates that there are plenty of nutrients in the water including phosphorus inducing the algae growth along with the white light.
The metallic taste and acidity probably result from corrosion upstream in your water supply.
Apparently there is not too much sodium bisulfite in your fish tank as the fish seem to survive The aeration enables the oxidation of bisulfite to sulfate.
Perhaps it is time to clean your fish tank and filter system. If needed replace the filter cartridge as well.
Regards,
Bruno