Pre-treat or NOT Pre-treat concrete for pressure wash?
Should you pre-treat concrete stains with chemicals before you pressure wash it? Does it make any difference on black algae stains? If so, what home household chemicals might be best to treat the concrete?
This is a 2000PSI electric pressure washer with a dual-tip cleaning disc. It is really under-powered for a fast job and this level of black algae but it good for demonstration here.
Oxy Clean (if anything) seems to make a bit of a difference. BUT, if you have a high powered pro machine, I suspect pre-treating concrete like this. is not really significant.
