Ro Units And Waste Water Amounts.

[stef_uk]

I'm seriously considering biting the bullet and buying an RO unit and salting it myself instead of forking out £30+ each time i buy water.

On a water meter here and have always been worried about the cost but have just had my water bill in and it costs me £1.37 per cubic metre of water which is 1000 litres.
By my maths a new RO unit would of paid for itself after 4 or 5 water changes.

Does anyone know approximately how much waste water is produced per uk litre/gallon of RO produced?

Also,any recommendations for the make and model?

Thanks.

 

[Morri]

Wow £30 a water change seems very high but I guess you are changing a lot I pay £4 for 25L salted water lasts me 2 weeks so the time and effort in mixing my own is not worth it. (ofc I test the salinty and nitrate levels before adding)

On your bill you need to check waste as well as if you are metered you get charged waste as well for that 1000L as they assume you use the water so you waste it as well.

There are a few people with more experince than me here but on average at tap pressure 1 Gallon of RO generates 3 Gallons of waste this can be improved upon with the relevant pressure pump.

I think a lot use the hardware from RO-Man make sure you have a DI unit on it and also invest in a TDS meter to check water quality.

 

[jtnova13]

yah i'd say 25% is RO, the rest is waste. so 3 gallons of waste for every 1 gallon of RO.

 

[TigerIssey]

Be careful with water metres in the UK, there is a thread in chit chat I have put some detailed stuff on.

If you are paying for wastage (ie not on a septic tank) your RO water WILL cost you twice as much.

This is because whatever is used through the meter is also charged as waste on top. I will add a link to this thread to the workings out I did on another thread when I find the title.

Have a read of the info I put on this thread

This link

It explains it in detail

 

[stef_uk]

Thanks for the link.
I'm going to sit down with the water bill and some paper and work out whether it is actually worth getting a unit.i'll also have to factor in the cost of salt to make my mix up.
It costs me £6.50 for 25l of saltwater and £2.50 for 25l of RO.

 

[TigerIssey]

Your in Lancashire too, that means its United Utilities that are ripping you off the same as me.

I am lucky though, I am on a water meter but use a septic tank. I thought your water cost looked familiar.

Don't forget to factor in the cost of changing membranes and the actual filter media too. I think its resin.

 

[stef_uk]

Yeah i'm in Brierfield.Its a new build so came with a water meter.
Just thinking though,my parents are only down the road in Nelson and in an old house with no water meter..I might find out if it would save me some money running a unit at their house haha!

 

[TigerIssey]

It would definately save you money if you used your parents house.

Ours is not a new build, its 245 ish yrs old but at the time that rateable value ended in 1990 the house was part of my next door neighbours house.

In 2004 the 2 properties were seperated to how they were originally built meaning a new dwelling was formed. Hence we have a water meter. Luckily though, we have a septic tank.