Most of this is copy and pasted from other posts.

We use potassium monopersulfate never used CH for cold weather cleaning. I think it really works well.

We have used it and it seems to help with roof cleanings. We thought we were going to need it yesterday, but we only have siding to wash all day, no roofs. We were down the Jersey shore doing a condo complex and it was 44 degrees when we started at 7:15 AM, but had no issues with a 1% mix on the vinyl siding. If it was a roof cleaning I would have most likely put 2-3 ounces in the first one or two roof tanks.

I use Fresh and Clear from Leslie's pool supply. It is a potassium monopersulfate based granular product. Use 2-3 oz. per 50 gallons of mix. it will burn a mix up in 5-8 hours depending on temperature. It oxygenates the bleach and makes it work faster. But it will start to turn it if left too long in a tank.

Also make sure your sh is fresh. We use 5 oz of the fresh n clear. Then we make sure we mix
It very well for about 3-5 minutes. We also mix it in a 5 gallon bucket while we make the mix for the roof then just dump the bucket into the tank. We have been using this stuff since 2011 and it does speed things up.