Advice required for very very green glass canopy.

[Eddie dragon]

Looking for advice on chemicals to use on a seriously green canopy. Someone has already had a go with a pressure washer and it looks like he achieved nothing at all. I have done green conservatory roofs before using just soapy water and wfp . This however looks a nightmare its on a school so really big.and never cleaned in over 15 years. 8 foot long panels over 200m of it and got 2 days to do a good job. Help please

 

[Pjj]

Weak hypo mix will dissolve it very quickly if you are happy using hypo and will need minimal scrubbing then good rinse job done .

 

[Eddie dragon]

Never uses hypo but happy to give it a go. However I read it can etch or make glass milky . Something I definitely don't wont to happen. What strength hypo would you use please

 

[Pjj]

Never uses hypo but happy to give it a go. However I read it can etch or make glass milky . Something I definitely don't wont to happen. What strength hypo would you use please

Never had any issues using it on glass even if it’s dried in hot weather , if it’s 10% strength I would dilute it 6 parts water to I part bleach give it a few muinits ti dwell after applying tge green algae will start breaking up and go a brown colour scrub rinse job done , if you are worried try a small out of the way patch first to give yourself more confidence.