Well water TDS and RO/DI unit

[Tazmaniancowboy]

I just found my TDS meter and checked my water supply in the house. It appears to be 71ppm straight from the well and 110ppm after the water softener. This doesn't seem right to me. Could this be true? If so, should I hook up the RO unit before or after the softener?

Logically I believe I should hook up to the well side so that the RO has less to filter out, but I'm not sure. I am confused? anybody else run into this situation?

Taz

 

[bconn]

Before the softner.

If your runnng a booster pump you should consider prefilter between well and pump.

 

[Tazmaniancowboy]

Bconn thanks for the reply. I'm curious as to why you say this? Is it because of the numbers I posted, or do you know by factual knowledge or experience. I am not questioning to try you, I just think if there is any facts on this situation it would be great help to other reefers with well water. I have never seen any info or posts on it myself.

Thanks again
Taz

 

[Hawkeye]

My tds is horrid before the softner. I personally find it strange your numbers are "backwards"...but then again maybe mine are.

 

[Tazmaniancowboy]

Phil, I thought it was strange myself and thought that maybe I had switched the samples. I rechecked everything with new marked samples this time with the same results. I have been wondering how this is possible ever since I discovered it. I am hoping others with well water post their findings. I am really curious now. There was an issue when the previous owner had the water test certification done 3 months ago for me to buy the house, but all they had to do was tweak the softener a bit to come back into spec. I have the before and after water reports, but I do not know what I am looking at!

If I don't get many replies I may start another post about well water

Taz

 

[stcreef]

Those numbers are perfectly normal. I have the same issue here. A water softener exchanges calcium and magnesium with sodium. This is why you add salt (sodium chloride) to your softener. Its exchanging one for the other. So it is entirely possible to see a higher tds after the softener.

 

[Tazmaniancowboy]

Thanks Stcreef, The numbers sounded odd to me, but thanks for clarifying. Now does it matter where the Ro/Di is plumbed?

 

[pgordemer]

It is usually recommended to be plumbed before the softener. The calcium (Salt) added in the softening/purging process tends to foul the membrane early.

 

[stcreef]

With those lower numbers it really doesnt matter. When the numbers are up in the 200-300 and higher range it can make a big difference. In either case though trials have shown with well water its better to have it after the softener. This is because the softener can get rid of more than the calcium and magnesium. So the only thing your ro/di has to really work on is the "sodium".

 

[Tazmaniancowboy]

This has really got me curious. My brother has his after the softener. I want to go to his house and do TDS readings on his system. In the meantime I have e-mailed Airwaterice to see what they have to say. I'll let you know.

Taz

 

[Tazmaniancowboy]

Thanks all for your replies. Here is the reply I finally got from AWI.

Actually, you have really good well water. Install the unit after the
softener. Hardness will kill off the RO membrane.

Regards,
Don
Air, Water & Ice LLC

Taz

 

[stcreef]

yup,

calcium and magnesium (the hardness in well water) doesnt flush too well from a membrane. The softener replaces them with sodium, and the sodium flush pretty well from a membrane.