[jikwan]

i havnt been using DI for months-no need RO is000
that might be the reason why algae forms a lot more
ive tried using a pound of rough sand mixed with water
and swilling it around   gets most of it off
just wondering if theres a better way

[Dean Aspects]

Try a power washer

Dean

[Simon_King]

Why not try diluting some Jeyes fluid and using that?

[jikwan]

im sure the power machine wil do a perfect job quickly
probably cost 50 quid a day to hire one though

the jeys fluid sounds promising

[Jeff Brimble]

A 10-20ml  of Milton in 2L of water, swish it about and let it stand for an hour. You could use domestos but Miltons kinder. You can still use the mix for the next container.
Give it a rinse as its got lots of salt init.
Its the sunlight that causes the green algae to gro.

[jikwan]

sounds like the milton thing is a proven method
guess i could get it from wilkos

i always wash my car by hand so ive never been anywhere near a carwash
garage  dont some of these carwash outfits have powerwash facilities
for a couple of quid a time?