TDS Meter

[Reefnut2010]

So I finally hooked up a TDS Meter to my RODI. Its reading 10-12 ppm after membrane and 0 after DI resin. I take it this is very good?

[Misled]

Need to know the TDS of the original tap, but yes, you want 0 at the end.

[Reefnut2010]

I was not too interested in my tap reading, as I'm sure is less than desireable....lol. I'm more interested in keeping an eye on membrane performance and final outcome past DI resin filters. Maybe later I'll add a single Meter to the tap line just for curiositys' sake.

[Buckeye Hydro]

You want to know your tap water TDS so that you can calculate your membrane rejection rate. Here' the single probe meter that is similar to the DM1:
http://i224.photobucket.com/albums/dd293/BuckeyeFS/sm1337.jpg

Russ

[Buckeye Hydro]

Called the SM-1

[Breadman03]

I just unhooked the probe from my RO side, dipped it into a cup, and swirled it a little. 370 TDS was the result, with 10-13 coming out the RO and 0 out the DI. I use the BRS 5 stage plus.

(Sorry Russ, but there's a few things in my wish list that will be coming from your shop.)

[Breadman03]

I just unhooked the probe from my RO side, dipped it into a cup, and swirled it a little. 370 TDS was the result, with 10-13 coming out the RO and 0 out the DI. I use the BRS 5 stage plus.

(Sorry Russ, but there's a few things in my wish list that will be coming from your shop.)

[Buckeye Hydro]

So you have a rejection rate of about 96%. Not exceptional, but pretty good.

Also - be aware that your 370 reading is not precise as the meter was calibrated with moving water...

Russ

[allsps40]

Yeah that is pretty good my SpectraPure 90gpd unit with new filter and membrane done around 10ppm after the membrane and 0 after the DI. After about a year it goes up to mid 20s and then I will change out the membrane. Be sure to replace the prefilter and carbon filter every few months, chlorine will damage the membrane and the carbon filter removes the chlorine. My tap water is over 400ppm.