RO Systems

[adamangler]

Can someone point me in the right direction regarding RO systems?

Ive read bits and pieces but im not sure what to get, is this all you would need?

http://www.ebay.co.uk/itm/300gpd-REVERSE-OSMOSIS-SYSTEM-POLE-WINDOW-CLEANING-AQUARIUM-DISCUS-MARINE-RO-/251131623707?pt=LH_DefaultDomain_3&hash=item3a789c791b

when they say 300gpd is that what it can produce in a day? thats about 1500l or is that including waste because it says 26l per minute pure produced?

i will be moving into a house with an outside tap, do i literally connect this to a the tap and output into a big container or can this be kept on van and hose feed to it to fill up tank overnight?

is there a better system?

thanks

 

[gto]

this RO is unpumped so will need very good tap pressure.

you will be better of with a pumped version, then a 300gpd will produe around 40l-50l per hour of pure water.

but this is still not 000ppm, so you will need a DI as well.

i have a vyair RO try their website for more info.

 

[spruce]

The figures quoted are in American gallons (smaller than a British gallon) and are given at a high pressure and at optimum water temperature in laboratory conditions. A day is 24 hours not 12. So for us, they mean very little with cold water etc. It's similar to new car fuel consumption figures quoted by the manufacturers, impossible to achieve in real everyday driving.

We could manage with enough water for 2 cleaners using a 450 GPD unit but we were processing water into an IBC tank holding 1000 liters 24/7. It would take about 28 hours to fill the IBC tank, a little longer in the winter - colder water is more dense (ice is solid) - about 32 hours. Sometimes, we needed to plan and welcomed a wet day so the r/o could catch up - not good business sense.

If you want to fit it into a van, then minimum would be a 4021 but most chose a 4040. (The van will need to be heated to protect the r/o from frost during the winter.)

We have replaced our 450GPD with a 4040 as we needed more water which the 450GPD couldn't provide. Our 4040 is unboosted at 50 psi, HF5 membrane and produces around 2 liters (actual) of pure a minute which is more than enough for the 3 of us. We still have the IBC tank that we process water into.

The figures quoted for a 4040 are 2400 US every 24 hours, but 'at the rock face' we get about 720 US gallons every 24 hours. So that's around 30% of what the manufacturer quotes.

 

[adamangler]

Thanks spruce, i think i understand some of that.

Basically i want the cheapest possible setup whether thats mounted on the van or to fill an ibc im not bothered at this time.

I only use about 1500l per month at the minute

 

[spruce]

What's your tap water tds and are you on a meter?

 

[adamangler]

Dont know yet not moved in.

I would guess 160 as its not far from where I live now and yes probably a meter

 

[spruce]

Dont know yet not moved in.
I would guess 160 as its not far from where I live now and yes probably a meter

If it is that then why not consider this;

At £80 for 25 liters of resin it will cost you £35 pm to purify 1500 liters - no waste water. This is less than 2.5p per liter resin cost. (A 300 gpd r/o usually has a 3 to 1 restrictor so for every one liter of pure you make you use 4 liters of tap water - 3 going to waste down the drain. So consider the cost of 4500 liters of waste water against the cost of resin.

Using a 7 liter di vessel would mean you would have to change resin every 3 weeks. When you do start to use more water then you may need to rethink this approach.

 

[adamangler]

Yes mate that sounds about right used 2 sacks of resin in 4 months.

Probably not worth the cost of buying an RO for now.

Going off that around 50p for 25litre d.i only. enough for an average semi so not bad at all really.

Think I will wait to find out tds/meter situation first

Maybe setup a few tanks for rainwater harvesting for now.

Cheers spruce