How big of a tank to get/how much sh for driveway?

I bought a downstream injector but because my pressure washer has weird size fittings I can’t use it. So instead I opted for a hand pump I understand this will take forever but I am just starting out and barely getting any customers so I don’t mind. I need to know about how much sh I need to use on a driveway to know how big to get the pump so my question is how much 12.5% sh do I need to cover a 1000 sqft driveway. I don’t need anything precise but just a rough estimate because I have no idea and all I could find on this topic was for roofs or houses.

I guess like 5 gallons, you’re only going to put down about 2% concentration.

I’m assuming this is just for post treating.

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thanks for the quick response and it’s for pre and post

Unless the concrete is seriously bad with lichens and nastiness just do a 3% post treat and call it a day.


I don’t have the best machine so I think pretreating would be a good idea for me to speed things up

Have you looked into getting an adapter for your machine to convert to more standard threads so you can use the common stuff?

Having so many things stringed together dosent seem the safest at such high pressures but the convenience is making me reconsider

We all try to limit connections to minimize leaks…but shouldn’t be a safety issue if done properly.

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take a pump sprayer and fill it with water and spray down your driveway. Pretend water is sh. Now you know how much you need


How dare you bring common sense to the table lol.


Wont happen again


That would be a pretty good method but I don’t have a driveway or a pump, I’m using this to determine the size to get

Measure out the road or sidewalk or go to a park or something. Get a 1 or 2 gallon pump sprayer. Fill with 1/4 sh and the rest water. That’ll get you roughly 3%.

I would recommend not using bleach at the park but just fill it with water to see how many sqft you get out of 1 gallon


Sounds like a plan thanks for your input

How big is your sprayer? If youre as broke as I was when I was 16 buying a 12v system is out of the question until you get more business. Making a 3% mixture in a 5 gallon bucket and brushing it on with a boat brush would probably work better if you have one. What kind of PW do you have?

I have the Simoniz 2700 PSI Gas Pressure Washer, the end of the hose has a female quick connection but where it connects isn’t quick connect it’s screw on and it’s 5/8 inch so nothing is compatible with it.

Just get you a one gallon SH chem sprayer at Lowes and keep refilling it. They’re cheap.


Yeah I was originally thinking of mixing everything every time but if I need to do this more than a few times it will get very time consuming and tedious but mixing the water, sh and surfactant together then just pouring in the pump dosent sound too bad so then it’s size wouldn’t matter much

Why don’t you just downstream?

…and…we’re right back to where we started :joy:

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