It allows you to more easily control the strength of your chemicals and allows you also to use a stronger mix. With downstreaming, you can typically only get around 1% solution of SH, which is fine for soft washing things like vinyl siding, but it’s not really strong enough for flat work, especially mossy pavers, or for roof cleaning. X-Jet I think lets you put out about a 3% solution depending on your GPM, but that’s still a few percent off from what you ideally want to use for flat work or roofs.
Youtube search for “soft wash pump system”, there’s a bunch of awesome videos on there.
