DS Injector won't pull enough for good SH ratio

So, I just upgraded to a 9gpm machine with 200 ft of pressure hose and have been testing it before I actually go to a job with it. 2 have happened that I can’t figure out. First, it doesn’t matter which size DS injector I use, I can’t pull at more then a .6 percent assuming im using straight 12.5% SH. nI did a bucket test and im getting 9gpm. I heard I was supposed to downsized my injector from watching one of @squidskc videos since im using 200ft of hose. @squidskc I am using the GP injectors you recommend. I have tried all of their sizes .083, .086, and .098 without a tip on them and they all draw about the same. I did tried all of these with just my ball valve on. Im not sure if it matters but I am using a Schertzbox to turn my chem on and off also.

I then put on my gun and used a 6560 tip (should draw solution) and it didn’t draw anything into my injector. I took purposefully didn’t schedule any jobs for a week or as so I could set this machine up and make sure its working well. I have a couple grand scheduled on Saturday and don’t really want to reschedule them since my calendar is booked for the rest of April and half of May.

I am at a loss for what is happening and don’t really want to take everything apart to put my 4gpm back on. Any advice would incredibly helpful! I attached a few pictures of the injectors and of how I have it plumbed.

I also run a homemade remote box and frankly it will be restrictive with the extra hose length and various valves to work through.

Try this, run a short hose into a gallon jug straight out of the injector and measure that. The box is a long way away from that machine with a lot of hose length to go through.

My 5.5 doesn’t pull near as hard as my 4/4 did, so an 8gpm like yours just won’t draw much to begin with, maybe 1:15 at best.

1 Like

Im going outside to try that right now. Ill let you know how it works.

1 Like

With 200ft of hose and 9gpm don’t expect to have a strong percentage at the tip. Keep that injector hose to a minimum, you could almost cut it in half

That didn’t work. I used about 3 feet and it still took 2 minutes to drain 128 oz of water. Maybe my math is wrong but that would make the ratio .74%.

That actually sounds about right for a 8gpm. I get roughly .8% out of a 2.1 injector with my 5.5.

If I want a stronger 2-3% mix I go with the xjet.

I guess I had the goal of 1%. I alway got a 1%-1.2% with my 4gpm so I just assumed thats what I would get with this larger machine.

What gun are you using?

Suttner ST-2605

Man, if you’re just softwashing a vinyl house, .8% is plenty to kill green algae and mildew. 1.5% is way too much.

1 Like

Wow, ive had unrealistic expectations then. When I first got on this forum last spring I read someone saying that right around 1% is where you want to be, so thats always what I shot for. Looks like I’ll have to move my Schertzbox closer to the injector and shorten the hoses, then try it again.

Any idea why my 6560 tip wouldn’t pull any chem at all?

I am fairly new at all this, the other guys will be along shortly to give a better response.

All I know is my LP jrod tip for the 5.5gpm is 2540 and it draws around .8%. Maybe yours being a 65 degree? Dunno.

I appreciate your responses. I thought I was past the novice stage this year :slight_smile: Guess I got more learning to do!

1 Like

@WiscoWashPros try moving your injector further downstream from the pump. I’d recommend putting it right at the swivel inlet of your hose reel.


I thought about that. My hose reel is right next to the machine so the line is about 2 feet long. With the whip lines I have, I can move it about 4-6 feet away from the pump. If you think that will help, ill give it a try tomorrow.

I’d bet a shiny penny that it will help. You’re not going to get 1+ % with a 9gpm unless you’re force feeding. .7 is sufficient to wash almost all vinyl or painted surfaces. Stucco and other more porous substrates will require slightly higher.

Ill give it a try. 90% of houses here in Wisconsin are vinyl or aluminum.

Good luck buddy.

I would try a 1/2” whip line from the machine into the reel and move your injector away from the unloader too. Once you get up and running these will help get your ratio stronger. If you want there is a way you can get 3% on an 8gpm so somwhere in that ball park for your 9 2.6 to 2.8% at the nozzle.


Where can I buy an injector fr my 8gpm that will get me 2.8% at the nozzle?

1 Like