Voted Other problem/not described.
Got green algae buildup this summer, with 5 months old distilled & WW3% mixture.
Must have been contaminated during refilling of T-line, even though I used a bit of cloth
soaked with antialgae toxins as a plug. This stuff took about 2½ weeks to grow.
All lines were coated with a thin green algae-film, so they went into the trashcan.
I didn't even try to manually rinse the hoses, as I would have to clean out both
the algae and the WaterWetter staining, too much job.
Couldn't detect any algae buildup in pump/block/rad, but poured in some of the algaetoxins
anyways.
Cut out some new hoses, rinsed every component with strong disinfectants to kill any existing germs/algae, took a shower, used disinfectants on myself
, in order to get the whole assembly process as sterile as possible.
Now my coolant consists of distilled water, 2,5%WW and a few drops of Simazine 0,5%.
I also have got some waterbed anti-algae stashed away, in case I need to use something stronger... It's active compound is Alkylbenzyldimethylammoniumchloride... Extra strong mixture the bottle reads...