I have a 300 gallon buffer tank and a 4000 PSI 4 gallon per minute unit. I’ve seen where people say you can’t use a tank without an assisted electrical pump. Is that so? I have a customer that doesn’t have on site water access and needs it done by Friday.
Job is a 32ft pull behind camper in a state park. Typical sap/mildew. Gonna use SH and elemonator mix.
Do u have Belt drive or direct drive? If u have a belt drive then ull be fine.
Direct. But I’ve seen direct drives plumbed with no pump. 
@Steve is one of those people
As long as you have a good gravity flow, and you can get the pump to prime properly, you should be ok.
300 gallon tank should provide plenty of head pressure to accomplish what you want to do, provided you plumb it properly.
Adding an additional pump to make up for a poor layout is a recipe for disaster.
What Alex said above. With a direct drive machine you just have to make sure you have enough water to ensure enough gravity flow to the pump. But I agree with Alex, as long as you plumb it correctly you should be fine with a 300 gallon tank.
Gravity feed it will help
You’ve got a machine and a 300 gal tank and you don’t know whether it’ll draw? Go out in the yard and find out. Sheesh.
It will draw… use minimal hose length and be easy on the bends
The myth that a direct drive can’t be used with a buffer is false
Thanks guys just wanted to be safe than sorry!
My direct drives will pull water with barely any water in the tank figured that out by accident, just pull the bottom plug on the other side of the pump to let the air out before starting your machine.
Before you plumb into the pump run a flow test from you tank. That will tell you what available supply volume is available to the pump. Just format your test to simulate the same height the intake on your pump will be. If you are dedicating that tank to your pump, I would suggest re-directing your unloader back to your buffer tank (plug the abandoned orifice on the pump, of course). Should work like a charm. Also, it’s good to have a filter(s) in your system.
This is not how operate effectively or efficiently. Get good equipment, set it up correctly , make money. @Steve had a postt earlier on how often he has to rebuild pumps and pulls from a tank using direct drives
See why I’m conflicted lol
Your right but a direct drive 5.5gpm pump will get the job done the same as a 5.5gpm belt or gear. Those direct drives will last plenty long enough to pay for everything on that trailer and more then I’ll buy gearbox pumps. As long as you keep more than 75gals in a tank thats plenty for two pumps most of the time the water from the house will out run one 5.5 and only lose a little bit water in the tank when running both pumps where i live, but i got my valve set at 150gal to make sure to not hurt my pumps
Found it:
Doesn’t sound like a ton of maintenance for direct drive pumps. I know Steve does a mix of windows and power washing, but still doesn’t sound horrible. I’m guessing his repairs have more to do with running direct drive pumps with their higher rpms, than running them off a buffer tank.
Wouldn’t be my first choice, either, but not a bad way to get started. Just make sure to have a gear drive on standby as soon as the machine has paid for itself.
