RO/DI storage container causing high TDS number?

[abinder]

Yesterday, I picked up this TDS meter from MarineDepot:
http://www.marinedepot.com/HM_Digit...iums-HM_Digital_Inc.-HB00017-FITEMOMI-vi.html

I was playing around with it yesterday checking the water quality of various sources at work and at my apartment.

2 drinking fountains at work measured about 410 and another drinking fountain at work measured about 575.

Water from a faucet at work measured about 525.

The bottled water that is delivered to work measure 44 coming out of the tap of the 'water cooler'.

When I went home, my tap water measured about 525. (the same as the faucet at work)

I then poured some water out of the 5 gallon container of RO/DI that I get from the lfs and measured it. The TDS reading on that RO/DI water was 85 !!!!!!!!

The container looks clean and I only use it for hauling/storing RO/DI from the lfs. Is it possible the container could be causing such high TDS readings of the RO/DI water?

Any info or suggestions will be greatly appreciated.


Allen

 

[CoralClark]

I would guess that ur lfs has high tds coming out of there system

 

[redfishbluefish]

It's your LFS! Buy an RO/DI unit and make your own!

 

[abinder]

It's your LFS! Buy an RO/DI unit and make your own!

I'm looking into getting the SpectraPure MaxCap90. I talked to someone at SpectraPure today and it seems like that is the one to get. The nice things is, he didn't try to sell me more that what I needed.
(I was actually thinking of getting the MaxCap180, but he stated that would probably be a lot more than I would be needing since I'll probably only be making 20-25 gallons of RO/DI every week.)

He also told me that I'll probably be getting more like a 3:1 waste/good water ration since the water in my apartment is so hard.
(He also stated that California supposedly has hard water.)

The MaxCap series supposedly come with a 'red' colored flow restrictor tube and a green flow restrictor tube. The green tube is suppose to get a better waste to good water ratio, but will clog the membrane faster. He suggested that I use the red tube, but stated that I could try the green restrictor tube since I won't be producing a lot of RO/DI water each week.


Allen

 

[fab]

I have the Spectrapure maxcap and the uhe version. Over the long haul the uhe is more economic because the media costs end up being so much lower. But the length of the 'long haul' depends on how much RODI you make. I make a lot so it works well for me.

Don't get carried away trying to optimize the flow restriction beyond the settings they recommend for your specific source water, including both its tds and its pressure. What you are after is 0 tds out of the DI stage with the 'right' amount of flow restriction for your source water quality (or lack thereof) as recommended by the tech guys at Spectrapure.

You will do very well with your new unit.

 

[abinder]

I have the Spectrapure maxcap and the uhe version. Over the long haul the uhe is more economic because the media costs end up being so much lower. But the length of the 'long haul' depends on how much RODI you make. I make a lot so it works well for me.

Don't get carried away trying to optimize the flow restriction beyond the settings they recommend for your specific source water, including both its tds and its pressure. What you are after is 0 tds out of the DI stage with the 'right' amount of flow restriction for your source water quality (or lack thereof) as recommended by the tech guys at Spectrapure.

You will do very well with your new unit.

Thanks for the info.

Is it possible to slowly upgrade a MaxCap to the uhe?

Thanks again for any info or advice.


Allen

 

[fab]

There is no such upgrade path that beats buying a UHE model outright from a cost perspective. Were there, I would do it immediately for my Maxcap.

You will get great service out of your Maxcap and from Spectrapure. You could possibly add stages if you have any problems getting sufficient purity. Understand, though, that does not improve efficiency. I doubt you will ever need to do that.

 

[Aqua fire/medic]

Just a quick question about the 5g Rodi container you got your reading from. Has it ever held mixed saltwater in it before? If it has them that is most likely why you are reading 85 on your TDS meter.

 

[abinder]

Just a quick question about the 5g Rodi container you got your reading from. Has it ever held mixed saltwater in it before? If it has them that is most likely why you are reading 85 on your TDS meter.

Nope. It's only had RO/DI water in it.
(I actually went by the lfs today and they poured a little RO/DI water out of their 'tap' into a plastic container. I measured it with my meter and it actually measured 95.)

When I got to work, I used the same meter to measure some DI water that we use there and it measured somewhere between zero and one (was 'bouncing' between zero and one on the meter). So, I guess that kind of proves it's reading the TDS properly.

I definitely appreciate the input though. I would never of thought of that possibly being the cause.

 

[abinder]

Just a quick question about the 5g Rodi container you got your reading from. Has it ever held mixed saltwater in it before? If it has them that is most likely why you are reading 85 on your TDS meter.

For future reference, how would you make sure a 5g container was clean enough for RO/DI water after it was used for salt water?

(Figured it would be good to know in case the need ever arises to use a 5g container that had been previously used for salt water.)

Allen

 

[BluewaterLa]

Just a quick rinse with a little RoDi is all that is needed.
I use four of the 5 gallon containers for getting water out of my 300 gallon storage container. I use the 5 gallons to refill my top off container and use them to mix saltwater as well. After using to mix saltwater in them I rinse soon after to prevent any fouling. Just had to use a little vinegar in the two oldest containers due to a slight build up in them.
Never had an issue, the slight amount of salt that would be left in there after you Empty it out wouldn't make a difference in your RoDi used for top off or mixing new saltwater.
Same as always just don't store them in direct sunlight where algae could possibly build up over time.

 

[abinder]

Just a quick rinse with a little RoDi is all that is needed.
I use four of the 5 gallon containers for getting water out of my 300 gallon storage container. I use the 5 gallons to refill my top off container and use them to mix saltwater as well. After using to mix saltwater in them I rinse soon after to prevent any fouling. Just had to use a little vinegar in the two oldest containers due to a slight build up in them.
Never had an issue, the slight amount of salt that would be left in there after you Empty it out wouldn't make a difference in your RoDi used for top off or mixing new saltwater.
Same as always just don't store them in direct sunlight where algae could possibly build up over time.

Thanks for the info !


Allen