TDS?

[seafan]

First of all I'd like to say it is nice to be back. I went on vacation to israel last week for thanksgiving (lol & pics are in the lounge). Before that I was out for the weekend so it has been a long time since I was last here. (wow that was a long introduction)

What is with TDS? The water out of the tap measures 202-250ppm. The water from my five stage RO unit measures 120-163. Nitrates are miniscule <2, chlorine is at 0, phosphate is at 0, However 120-163 seems really high. What's the deal? Does an RO unit not get rid of ionized substances?

 

[Bearfan]

That is VERY high, I think your meter is off. My inlet (from well water) is 85-95 and my outlet is 0-1.

 

[seafan]

How do I calibrate it?

 

[jaiden]

200-300 is not abnormal for source water. 20-30 is not abnormal for RO output. 160 is too high. something is wrong.

to get 0-3, you generally need a DI after the RO. Bearfan either has a broken tds meter or a very clean well.

 

[seafan]

How do you explain the readings for nitrates, and phosphates?

 

[Bearfan]

to get 0-3, you generally need a DI after the RO. Bearfan either has a broken tds meter or a very clean well.

Lake Superior water through a sand substrate. About as clean as a well can get.

And I do have a DI.

 

[jaiden]

I'd guess that the nitrates are being read by the tds meter. DI would help you, but putting 160 tds into a di will use up your DI resin in a hurry.

 

[seaham358]

You say RO so you have no DI cartridge right?
How old are your filters on the unit. Whats the GPD on your membrane. You can buy calibration fluid for a TDS meter on line.
If you have a DI then I would say its used up. What type of unit and what filters do you have. I have a Micron then 2 carbons then the membrane then 2 DI units. I get 0 TDS... Starting out with 280 TDS with 40 after the membrane.

 

[seafan]

No DI, just a 5 micron charcoal then another 5 micron charcoal, then one sediment, and two other sediments I think. It's a 75 GPD membrane. It is brand new just two weeks old.

 

[seafan]

can you send me some of your water to calibrate it seaham. send me a PM.

 

[jaiden]

Did you flush it out? RO's usually recommend discarding the first 10-20 gal or so. keep testing the tds.

 

[seaham358]

You don't use water to calibrate it, its a special fluid..

It also sounds like you have you filters in wrong. A micron filter should be first to collect sediment before it gets to the carbon.
What type of unit is it. And if its a new unit like the others said trash the first 10-20 gal of water.
I would rearrange the filters...... coursious on what kind of unit it is. With a 5 stage you could get ride of the last carbon ro micron and add a DI cartridge.
http://www.h2oinstruments.com/PH_Meters.htm
this is to give you a idea on what Im talking about with the fluid... Google for it.
Also if the meter is new it probably is ok and is just the way your filters are hooked up. Anyone near you have a TDS you can borrow to compair? How about the LFS.....Take some water for them to test if they have a TDS.

 

[seafan]

Thanks that might be it. I got it on ebay and had a plumber install it I'll rearrange the filter cartridges and check it. A DI unit would burn out very quickly in Miami so I decided not to get one.

 

[seaham358]

starting with a TDs of 200-250 is not bad at all. My friend starts with 700 and his Di works well.
Good luck

 

[seafan]

It really depends on what those solids are. In my case it is calcium carbonate.

 

[loganj]

Check your TDS meter in some distilled water. It should read 0-1 or very close to it. Not the best way to calibrate it, but it'll get you close.

 

[Sam]

I have a six stage: 10 micron - 5 micron - 1 micron - membrane - carbon block - DI cartridge. I get about 205 out of the tap and about 5ppm RO. My DI is shot because I am getting the same TDS out of the DI cartridge. Just changed all of the pre-filters as my pressure had gotten really bad. Could not believe the gook on the pre-filters.

 

[seafan]

It seems to be working my TDS is down to 6. Maybe I should get a two micron? I used my friends meter though. I think mine is broken, or maybe not calibrated properly.

 

[seaham358]

One way to tell is test with his then yours if there the same then it ok...
Down to 6 with no DI is great I do not think you will get much better then this with a extra micron.
Are you sure you don't have a DI cartridge in there... 6 is extremely low for just micron, membrane and carbon.
What unit is this and were did u get it???

 

[seafan]

I might, I don't know what two of the stages do. Actually now that Look at it im pretty sure it has a DI.