Di/ro

[brada95]

Don't want to sound to stupid but what's the difference between di and ro water? If I was to use di water over a period of time would it put the hardness of the water on the glass? As like stain it? Sorry if I'm been thick haha

Sent using the Window Cleaning Forums mobile app

 

[spruce]

Don't want to sound to stupid but what's the difference between di and ro water? If I was to use di water over a period of time would it put the hardness of the water on the glass? As like stain it? Sorry if I'm been thick haha

Sent using the Window Cleaning Forums mobile app

R/O is reverse osmosis. Water under pressure is forced through a very fine membrane and nearly all the dissolved solids are removed. Its like a filter. A good working membrane will remove about 98% of the dissolved solids in the water. We then pass that filtered water through a di vessel that is filled with resin beads. As the water filters through the resin, the resin removes the remaining impurities that weren't trapped by the membrane.

A di vessel with resin will remove all the dissolved solids in the water. The higher the tds value of the water, the quicker the resin will be spent.

Dissolved solids are minerals, calcium, magnesium and other salts. The higher the concentration of these dissolved minerals are in the water the higher the tds and hence the greater the hardness of the water.

If you wash windows with 0ppm of water there are no minerals left in the water to create hard water spots when the water evaporates. You can wash those windows over and over again without spots forming.

Some people with soft to medium water on a water meter might elect to go resin filtration only. It is general accepted that the economic cutoff point is a tap water tds of 100 or less if you are on a water meter. (An r/o uses water to flush the membrane of the impurities it has trapped whilst processing water. In most cases you can get away with using 2 litres of water to produce 1 liter of pure. On a water meter you have to pay for that 'waste' water as well.)  You can still use resin to purify your water no matter what your tap water tds is, but the higher it is the more expensive it will be as resin isn't cheap.

.

 

[brada95]

Cheers for getting back to me massive help mate cheers


Sent from my iPhone using Window Cleaning Forums

 

[spruce]

@brada95. Before deciding which way to go (di only or r/o +di) you will need to know the tds of the tap water you will be using.

So first stop is to buy a tds meter from a trusted supplier. They are cheap on Ebay but some of those are fakes/copies and can't be trusted to give an accurate reading.

Even if you end up buying water from another supplier you need to check the tds of the water you are buying, so it will always come in handy.

Saving a tenner on a cheap tds meter can cost you much more in the end.