[Matthew JN]

Hello chaps

Need so me advice from DI only users.   My tap water is around 265ppm.   If i changed to a twin DI set up - as in putting tap water in the van tank and 2 in line DI vessels then pump then inline tds meter to reel...

1. If im using on around 350 - 400 litres per day - doing 4 days a week - what size DI vessels would you reccomend ?

2. Do you DI only guys think inline tds meter is best way for this set up.

Thanks

[William McCafferty]

If your tap water is that high you need a ro unit, di from that and the quanitys you are going to use will cost a fortune in resin over the year

[mister bit]

I don't think the resin will last long .... could you buy some ro water from somewhere?

As much as I know you will start producing pure water then the resin will become exhausted this depends on numerous factors like the rate of flow the depth of the resin bed the temperature of the water etc. so a slow flow and the biggest di vessel would seem sensible from this scenario.

The double di system starts with only one DI until the tds rises then introduce a second di. When that DI tds starts to rise beyond a workable level. Fill the first DI with fresh resin and swap them round rinse and repeat (seems like an appropriate expression).

Inline tds meter seems ideal for this system.

Disclaimer alert I am not sure if this is correct but seems reasonable .....

If you are going for this why not introduce some pre filters as you fill up the tank to get some of the crud out of the water may save money in the end and possibly a softener because you can just keep regenerating it. This softener would remove calcium and magnesium ions which leave white spots on glass because of their extra charge (2+) Ca2+ Mg2+ and extra willingness to bond with whatever elements are knocking around  (extra sticky = extra difficult to remove with ion exchange resin)... that way you may get the cost down it's worth experimenting it could be the future and you could have a USP of not being a water waster window washer!

I also read that it's a no-no to let the waste from an RO unit go down the drain   but that was on a night time info trawl when I had had a couple of belgian beers so may be incorrect info (I was looking at a water authority site during the drought). Any opinions anyone?

[Matthew JN]

I current use an RO system with DI polisher.

Water is costing me £40.00 per month - £20 supply £20 drainage bill, plus I propably go through 2 bags of resin in a year for the polisher at £ 65.00 each and a new prefilter kit every 8 weeks at £15.00 a time.

Saw the clip on your tube of a guy who uses around 1500 litres per month similar to me - was using an RO but switched to twin DI and worked out it was only costing him  a few pounds more per month, but greater flexibility - fast filling etc.

Obviously excluding the purchase cost of any vessels.

[mister bit]

sounds like the furure if you can fill from customers taps on the way round must pay for the cost of diesel too .... have you got the link from youtube?

[♠Winp®oClean♠]

I'm a twin DI only veteran of over 8 years with a tap TDS of around 90ppm. I run a 400ltr van mount & use approx 3 bags of Tulsion MB115 resin per year (absolute maximum of 4 bags now I'm doing everything wfp & using a higher flow rate).

I would recommend using two 11Ltr vessels- big enough & still nice & manageable. I can't say how much resin you will use as that depends on what's in your tap water, your flow rate etc but look at it like this- You already have 1 DI vessel, so for the cost of one more you can try it with nothing else to lose.

Filling the tank with tap water & pumping through the vessels on board will give a slower flow through the vessels thus extending the resin life further.

[Matthew JN]

Hi the you tube link is...

http://www.youtube.com/watch?v=xLwTAjxDSuM


Was quite interested to see if this guys maths held up really - as really would like to go this route myself. He says his tap was around 250 ppm.   I know i would have no problem using my customers taps if neccesary.

He has 2 in line 17 inch vessels in the clip. Which is what i thought i should go for. 

BTW my polisher is a 10 inch filter housing with cartridge that i fill with resin to bring down to 000ppm - otherwise now about 005 comijng out of RO unit.

Question really is i know that vessels have a minmum pressure that they require to work effectively so really should the pump go before or after the reel for this. 

Inline TDS i see as a must have - as i always like towork with 000ppm if possible - no more than 002 if i had to.  So downside is the slightly irritating task of changing resin in the vessels.

The guy in the clip has both permantly in line it looks like - whereas one of you has suggested that although twin you only connect second one up when tds reading goes down on the first ??

What to do...

[mark m]

I am glad people watch my videos i used 2 27"twin di vessel and a get approx 6000 lt a month  i have tried this now for 5 months and within a couple of hundred lt it is about the same each time

[mikeyfaerosyth]

Take Winpros advice,tank- pump- twin di- reel- brush.Check every 2 or 3 days.I change mine about 007/8.

Refilling vessels does not take long.

And buy resin from Daqua

[♠Winp®oClean♠]

Have both vessels together, only when you start the process for the very first time would you start with just one.

DI vessels do not work on pressure, the water which passes through is not under any pressure.

[dd]

With a tds of 005 from RO personally I would not bother to use resin. As long as tds is an single figures water should be fine.

Also changing pre-filters every 8 weeks is extreme. They should last at least 4 months, maybe a bit more.

If you are on  water meter you should be able to claim a rebate for water not returned to the drain on the drainage element of your bill.