spotting on 0ppm WFP DI system

just set up my diy van with an internal carbon. sediment filters and 2 11ltr DI resin canisters, and also an inline TDS meter, all readings from my inline and handheld TDS meters say 0ppm but i am still getting spotting on the window, I would think techniques is isnt there, but any advice would be gratefully appreciated.

How dirty were the windows before you cleaned them? Were the frames dirty? Did you rinse enough? How high have you got the flow on? Is the spotting in a trickle line from the top of the window? Is the spotting all over the window?

Hi Tuffers, My windows are frames are in very good condition, (im only testing on my house for the moment) my flow is is 2ltrs per min and the spotting on 1 window is a trickle from top to bottom, and 1 window all over and the other look good with no issue, and im swapping between the flock gardiner brush and the sill brush, 

Assuming your water is '0' ppm, then it's your technique. Check the ppm from the water coming out of your brush head.

Oddly, it could also be the window frame itself, but my money is on technique.

Firstly don't use the flocked brush. Is your sill brush flocked?

Secondly you need to set your flow correctly (this is a very personal thing and is different for everyone). 

You need a fairly high flow rate. 

I'm not sure what 2lpm equates to, but when I turn mine on it travels 6 to 7 feet, when holding it at waist height.

I'm guessing you're new to this, so the flow rate may feel 'uncomfortable' and wasteful.

Let me try and explain:

If you're flow rate just trickles out, then when you scrub, the rate of water won't be enough to rinse the dirt away.

So will spend 2 mins, rinsing and rinsing to get the dirt off the glass. 

If your flow rate is too high, it will 'bounce' off the glass and come back to you.

In an ideal world, you are looking for a flow rate that will create a fairly quick 'curtain of water' running down the glass. 

The quicker you clean, (or should I say, the quicker you 'agitate' the dirt) then the quicker this 'curtain' of water has to appear, to rinse it away.

If it were me, I would increase the flow rate to what you feel comfortable with, then up it a bit. 

Naturally, when you have scrubbed a window, you finish it with a rinse (a curtain of water running down).

So the next is scrubbing.

You need to scrub more than you think (especially on first cleans). 

If you get drips from the top, then generally it is the frame, not the glass.

Give those frames a good scrub, especially the horizontal frame at the top of the glass (most important).

Trick:

Clean all the frame and the glass, do the whole upstairs front and back.

Go back to where you started and clean ONLY THE GLASS from about half inch down from the top of the glass. Don't touch that top frame again. It's clean. Leave it.

Hopefully the frames have stopped dripping and any runs that may be on the glass, you will now clean off.

Scrub more than you think (on first cleans) and get in them corners!

Hi Robbo, some really good detail in your reply, much appreciated 

I was starting to think that maybe i need to invest in a RO system inline with my 2 DI tanks, 

The Sill brush isnt flocked, and i much prefer the sill brush, feel like i can get into the corners a little better, 

with the flow rate i will test the length but i dont think im hitting the 6 to 7 feet at max

the system i have put in my van is a push from the pump., 

in order of fitting

500 lt flat tank,

mesh filter

through to pump, 

then onto carbon and sed filter

then the hose wraps around the back of the flat tank to the other side

then fed through the 2 DI tanks, then onto a eccotemp l5 water heater

then through the hose and pole.

The pump is at max, 

Im wondering should i get another pump or move this pump ive got closer to the hose and pole??

I will try your method tomorrow, 

Thanks again

It will probably be soap leeching out of the rubbers. Not a lot you can do except clean glass only on second wash. It will resolve itself after a few washes unless the rubbers are goosed

Hi Part Timer, thanks for your response 

it is odd how i get spotting on a couple of windows and not on others, 

Im sure my technique needs improving and ill be working on that with Robbo's advise, frames first, then glass while avoiding the tops of frames and more scrubbing, 

lets see how it goes

thanks again

SCT window cleaning said:

Hi Part Timer, thanks for your response 

it is odd how i get spotting on a couple of windows and not on others, 

Im sure my technique needs improving and ill be working on that with Robbo's advise, frames first, then glass while avoiding the tops of frames and more scrubbing, 

lets see how it goes

thanks again

Click to expand...

If it's the odd window then it's not technique. 

Agreed, water fine.

Re-do the glass but start from a cm or two down from the top black rubber seal. I still have the odd job where I don’t do the top frame as the black rubber seal bleads & leaves a streak. Or the odd time where I have to do the top frame, do that the top frame then glass, then re rinse the window carefully from a inch down 2-5 minutes later. 

My own bedroom window leaves streaks funny enough. The only way I’ve learned to not leave a streak is to clean the window exactly how I explained. Works for me, I’ll let you play about with yours. 

One thing to also watch out for on some houses and I even have this happen on new builds that are around a year old, on windows which have plastic trim across the top of the window so above the window frame itself the trim drops a little and causes a small split in the silicone and there can be a whole load of dirt trapped behind the trim overtime and this will drip forever almost as bad as trickle vents, so I sometimes have to place a cloth over the brush head to dry off the trim to avoid any dirty water dripping down. 

The one thing that I am curious about is why your filtration is after your tank in the van and not before? 

You're transporting regular tap water around in the tank and then filtering It on-demand when you're on site stop.

I have always found this very very backward way of doing things and believe that your water should be filtered before you start the day.

Isnt that down to presumable personal preference. as long as 0ppm is coming out the pole.

What's your tap Tds, I don't see an issue with your described on board set up if you have a low tds. 

just checked and TDS on tap is 250 and out of pole 0ppm

You are going to eat through resin in no time at all, the pre filters will hardly reduce your tds at all, basically you should have come on the here first and we would have advised you that you need an R/O

agree, my first canister is already at 38ppm and ive used only around 500ltrs, money was tight so i thought DI was the best and cheapest option.

Unfortunately not you will have to shell out for an R/O, if you are watching the pennies and have a really good credit rating and they still have do 0% credit cards that could be an option and pay it off before you get hit with the interest.