[jonny thompson]

Hi any ideas why my water after the resin going into the tank is 1 and never 0, before ro 70 after ro and before resin 17-20 after 1, I only changed the resin about a month ago
Thanks

[Spruce]

Hi any ideas why my water after the resin going into the tank is 1 and never 0, before ro 70 after ro and before resin 17-20 after 1, I only changed the resin about a month ago
Thanks

What r/o have you got?
What di vessel have you got?

Generally, if you have 70 before r/o and 17 - 20 after then your r/o membranes are shot or your have an issue with pure to waste ratio, water pressure or a mixture of all 3.

How long have you had your r/o?
Did you buy it new?
When runing the r/o, what is your pure to waste ratio?
What is your water pressure?
When do you  change prefilters?

[nathankaye]

Asabove

[simon w]

Is your tds meter accurate/working properly? Always best to have two hand helds to check against each other 

[jonny thompson]

Spruce what reading would you expect after the ro with my reading before of 70, I have recently been filling my van up at the end of the garden hence running a hose about 50 ft maybe it’s the water pressure, I’m happy using water that’s got a reading of 1 but why does it get it down from17 before to 1 and not o

[jonny thompson]

Also I have a ratio of pure 3-1

[jonny thompson]

Sorry me again I’m also using microbore to fill up the tank , I wonder if I used half inch hose would increase the pressure, if the pressure is to low would this damage the filters , ro, or just not get the water to 0 without any damage

[nathankaye]

My tap water before the RO is close to 300ppm and I use a booster pump after my prefilters but before the membranes and the water comes out at 009.

So I would expect using an RO with an input of 70ppm to take it to virtually 000. Perhaps use a booster pump at the end of your long hose pipe to increase the pressure.

[Spruce]

Spruce what reading would you expect after the ro with my reading before of 70, I have recently been filling my van up at the end of the garden hence running a hose about 50 ft maybe it’s the water pressure, I’m happy using water that’s got a reading of 1 but why does it get it down from17 before to 1 and not o

What r/o have you got?

It sounds to me that you have an on board unit so I'm thinking its a 4040 or 4021.

If this assumption is correct then you need to get rid of your supply hose. Microbore isn't good enough to supply the needs of your r/o. 
Your supply at the end of the hose needs to deliver around 9 liters of water per minute for a 4040 to work. That microbore will be restricting the water to the r/o and will be reducing the water pressure on the membranes exacerbated by your 3 to 1 waste to pure ratio.
With your low input tds you could well run at a waste to pure ratio of 55 to 45 or even 50 to 50.  This may mean replacing your waste restictor to on that will allow fine adjustment.

If your membrane was working efficiently then you should expect a rejection rate of 97 to 98%.

At the moment your resin is polishing off the high remaining tds. The reason why its not getting to zero is that it probably spent and the tds will rise. If you have just replaced the resin then the di vessel could be faulty, or your resin is suspect or your tds meter might be reading wrong.

Unfortunately we need more info to help you.  Hence the reason for all those questions.


 

[Dry Clean]

My tap water before the RO is close to 300ppm and I use a booster pump after my prefilters but before the membranes and the water comes out at 009.

So I would expect using an RO with an input of 70ppm to take it to virtually 000. Perhaps use a booster pump at the end of your long hose pipe to increase the pressure.

That's a strange set-up, I suspect your booster pump is doing very little or no work as the pre filters before it would be restricting the water supply, in other words the tap pressure is enough to stop this happening,

[Dry Clean]

Sorry me again I’m also using microbore to fill up the tank , I wonder if I used half inch hose would increase the pressure, if the pressure is to low would this damage the filters , ro, or just not get the water to 0 without any damage

Low pressure wont damage the filters, an RO membrane works by forcing water through it under pressure, less pressure just means more water runs to waste, a 4040 membrane is a good example of this as when you open up the tap and release the pressure nearly if not all the water runs to waste.

[dazmond]

Hi any ideas why my water after the resin going into the tank is 1 and never 0, before ro 70 after ro and before resin 17-20 after 1, I only changed the resin about a month ago
Thanks

i dont know why you bother with an RO with a TAP TDS of 70....you could save so much hassle with a DI only set up!very quick and easy!

[Slacky]

But if you have a TDS of 70 with an R.O. you don't need to buy resin.

I have a TDS of 300 and product water is 8.

[james peters]

Hi any ideas why my water after the resin going into the tank is 1 and never 0, before ro 70 after ro and before resin 17-20 after 1, I only changed the resin about a month ago
Thanks

i dont know why you bother with an RO with a TAP TDS of 70....you could save so much hassle with a DI only set up!very quick and easy!

mine is about 70 ish. In my last property I saved around £600/£700 a year by using an ro ...my tds was around 3
In 2008 I bought a new house and was on a water meter.
so now its not saving money. I buy a bag of resin around every 6 weeks . I agree it is easier, also, if I need to top up on the move its easier

[dazmond]

But if you have a TDS of 70 with an R.O. you don't need to buy resin.

I have a TDS of 300 and product water is 8.

maybe not but you ve still got to buy an RO,membranes,pre filters,etc and if your on a water meter extra water costs too...even if it cost you a bit more using a DI only system.itd be worth it for convenience alone......you can purify 500L in 30 mins then get on with the rest of your day.......great....

[nathankaye]

My tap water before the RO is close to 300ppm and I use a booster pump after my prefilters but before the membranes and the water comes out at 009.

So I would expect using an RO with an input of 70ppm to take it to virtually 000. Perhaps use a booster pump at the end of your long hose pipe to increase the pressure.

That's a strange set-up, I suspect your booster pump is doing very little or no work as the pre filters before it would be restricting the water supply, in other words the tap pressure is enough to stop this happening,

My tap pressure before and after the prefilters is 34psi and the booster takes it to 70.
Withoutthe booster on my product water is 014 and a slow trickle.  The booster produces quicker and more efficiently takes it to 009.
Buti use a 450 gpd ro

[AuRavelling79]

Is your tds meter accurate/working properly? Always best to have two hand helds to check against each other 

Yes - my two read slightly differently. "The blue" one reads a bit lower than the "cream" one.

Anyway I like the water to start at zero after new resin but soon the cream one show 001 and a few days later 002 and up. The Blue one is a day or two behind. 

But - as long as I'm under 10 TDS I don't really care. I've  used 15 when I forgot to check. No problems.

[jonny thompson]

I’ve been and bought some half inch hose, so hopefully this will sort it, dazmond I take it a di system is just the two filters and resin

[jonny thompson]

Spruce are you saying I should be having  the same about of waste as what goes into the tank, ie 50/50, usually I have been having about 90% going into the tank with just a trickle of waste but I wasn’t using 30 meters of micro ball back then , I was just running a couple of feet of half inch?

[Simon Trapani]

But if you have a TDS of 70 with an R.O. you don't need to buy resin.

I have a TDS of 300 and product water is 8.

maybe not but you ve still got to buy an RO,membranes,pre filters,etc and if your on a water meter extra water costs too...even if it cost you a bit more using a DI only system.itd be worth it for convenience alone......you can purify 500L in 30 mins then get on with the rest of your day.......great....

When you getting your RO then Daz?