[Alex Gardiner]

Hi Macmac,

Whilst I agree with many of your thoughts you post, I feel that you have presented a very one sided opinion with your last comment. (which of course you are perfectly entitled to do!)

Here is my take on the situation:

I also have soft water at about 078ppm TDS. I have been using very simple RO units (200gpd un-pumped Ro-Man type) for about 6 years now. Whilst there are some issues to do with storing the product (1000ltr IBC) and transferring the product (submersible pump) these are easily worked with.

I have the RO running about 70% of the time into the IBC; we have 3 workers which work off of this set-up, filling into 2 different vehicles in the morning as they need it. We use on average about 2500 ltr of water a week.

This equates to about 288 weeks of water which equals about 720,000 of product water over the 6 years.

This has cost me over the last 6 years:

2x RO units = £350 (retail)
Pre-filters = £120 (retail)
Post filter resin = £15 (retail)

Total cost for 720,000 ltr = £485
Cost per litre = 0.0674 pence

If I had been using a DI only system this would have been my expenditure:

1 sack of resin would give me on average 6410 litres of product water with an input TDS of 078ppm.

I would have needed 112 sacks of resin at a retail price of £69 per sack this would have cost me £7750

Cost per litre 1.076 pence

These are the hard figures for my type of work load. In my case, who makes more - the retailer selling you 112 sacks of resin for £7750 or the retailer who sells you 2x cheap ro units and a few consumables for £485?

Bear in mind though that we have a fairly high usage rate due to the number of workers (3) and the type of work we do. The average worker would maybe only use 800-1000ltr a week and may also be in a softer water area.

Quite often DI systems are the only option and we always try to talk through a persons requirements before advising on any system. For an average worker the weekly cost would be only about £9 for running a DI system with 100ppm TDS. This equals about £468 per year, which for many is an acceptable and hassle free option.

When water usage rises then RO systems become more beneficial, but also bear in mind that many RO systems cost a lot more than 2x a 200gpd RO-Man unit!

Phew.

[macmac]

Well done Alex.
I respect your views greatly.
Now, with your post in the equasion (spelling?) people can see both sides of the story & make up their mind to which system would suit them best.
Good, honest input from both sides of the fence

I wouldn't name any supplier (but it's not you ) but i have known them supply a completely over the top, un-nessesary water purification system for people with very soft water & when explained to the said persons what they could have had instead they have been pi**ed off say the least & changed systems. In these cases it was money not well spent IMO.For one of these in particular, having an RO set-up was a great hassle in the first place because of the type of house he lived in.

So, It's a case of cost Vs convenience & simplicity sometimes i suppose.

Oh, & just a thought Alex, does the resin cost that you present represent using 2 x DI units & shaking the vessels to get maximum life from the resin ?


tony

[macmac]

Just one other point, to be fair Alex, is that my advise is aimed at the average Joe, not someone with a massive round employing people & using hundreds of litres of water per day.

tony

[macmac]

Alex
I have just weighed up that using my system of things you would only use 36 bags of resin in a 6 year period, so that would cost you 2,834 quid as oppose to the 7,750 that you quote. Which would be 9 quid per week.
Thats on your water usage, not mine. & thats on 105 tds input.

tony

[DASERVICES]

I'm DI up in Scotland and looked at the pro's and con's of having an ro. For me it was simple as time is money and TDS is very low up here so decided to go the DI route, plus I also had to fill up at customer's houses.

Originally I used 3 - 4 bags a year, but now have just exhausted my first bag this year since using it in Jan. I changed product which I now sell up here, the downside I expected my customers to be ordering more now but they are still on the original bag. One info I have passed onto them is if you look after your resin it will last longer.

Using the 2 vessel idea is a very good idea your resin will last even longer.

I think it all depends on your TDS level what method is best for you. My usage is around 84,000 ltr a year and my cost for resin £130 a year which is not bad.

This works for me but may not for others.

[macmac]

my figures are very close to yours also doug.

tony

[Luke Johnson]

I have a tds of 34 here, you can use a hosepipe with tap water to clean your windows without spots!!!

[macmac]

I have a tds of 34 here, you can use a hosepipe with tap water to clean your windows without spots!!!

Where luke?

tony

[Alex Gardiner]

Hi Macmac,

I think that between us we have offered a good option of views for everyone. I think that your 2 resin vessels system is probably more efficient than the single vessel figures that I was using. (500,000/TDS=litres per 25litres resin)

I personally have never used a twin DI system myself. In fact it was only this week that I used for the first time, a DI vessel for my own work. I have a converted chapel where you cannot get a vehicle to, but it does have an outside tap and soft water. I made up two short hose reels and an 11ltr DI vessel and walked to it. Worked a treat.

If you were looking at spending £6000 plus on an RO system then the figures would not be quite the same as it would take a very long time for the average user to spend that much on resin (about 13 years on 100ppm TDS).

Of course if you are in a hard water area and a lot of our customers are, then purifying 300+ ppm TDS with resin would be extortionate, RO is the only option.

[Luke Johnson]

its Wales