How long of a hose can I use

[Jersey Bill 17]

I have a 4 GPM, 3.5 PSI belt driven cold water machine. I currently use 100ft of hose (two 50 foot hoses) for my jobs.  I see guys with trailer rigs that have well over 100 foot of hose on reels.  How long of a hose can you use before it stops drawing soap?  Or is there formula to know for the size of the machine and length of hose?

[RalphQ 5]

Use the smallest orifice you can find. I use a 2-3 gpm injector on my 5.5 gpm machine and can draw soap with 350 feet. If you have to, you can put the injector midway in between hoses, with a bucket.  

[ckeener 30]

That's how we do it. If we r not pulling around all of your hose put the injector 100 ft from end and it will cut down in the draw time.

[Guy B 70]

We run 200' and rarely have a situation where we need more than that.

[GTRider245 14]

I run a 4/4000 machine and with 200' of hose a 2-3 GPM injector works much better than a 3-5. YMMV.

[Chatham Property 0]

I use a supper sudds sucker and it is as advertised no problem draw chemicals at over 300'