What's the TDS of your tap water?

Humblefish · Jun 7, 2015

I would be interested in hearing results from all over the world, as I know we are a diverse bunch here.

Also if you can't get the output of your RODI down to 0 for some reason, mention that as well.

Me: Monroe, (North) Louisiana, USA
Tap: 86
RODI output: 0

M3ace9 · Jun 7, 2015

Tap at 86 is amazing. Cities with dirtier water are in the 500s and burn through lots of DI to get 0 consistency. My tds is 240 in and coming out of my dual membranes I am getting 3 with a 2.5 to 1 ratio. Not too bad but could be better like yours haha

Calmbeast · Jun 8, 2015

Tap is 200 here in Eastern PA. I am currently using ro/di from the Weis grocery store.

menglish · Jun 8, 2015

I am in Silver Spring MD and the TDS out of my tap fluctuate between 8-11 ppm. The water out is usually 0 but now it is reading 1ppm. I guess it is time to change the membrane. I am also lucky because the water pressure out of my tap is 100 psi, no booster pump needed. I usually make my RODI water at about 80 psi

hejjo · Jun 8, 2015

Chicago Illinois suburbs. In 350 out 0

Up2no6ood · Jun 8, 2015

42 outta the tap in Montrose MI

Shep · Jun 8, 2015

menglish said:
I am in Silver Spring MD and the TDS out of my tap fluctuate between 8-11 ppm. The water out is usually 0 but now it is reading 1ppm. I guess it is time to change the membrane. I am also lucky because the water pressure out of my tap is 100 psi, no booster pump needed. I usually make my RODI water at about 80 psi

Hmm, I'll have to see what mine is because I'm in Frederick and I wonder of different it is.

Randy Holmes-Farley · Jun 8, 2015

FWIW, everyone can get the TDS of tap water down to 0 ppm (measured in line) if they have an appropriate DI resin.

I'd also caution that while interesting to note, tap water TDS is not a measure of whether the water is suitable for a reef. It is just a measure of saltiness of the water. For example, tap water with 5 ppm TDS run through copper pipes might have way to much copper in it, while 300 ppm TDS tap water without such copper (and other undesirables) might be fine.

That said, my tap water has a TDS of about 95 ppm.

danoleary · Jun 8, 2015

I'm in London UK and my incoming tds is 295 I get 0 out but burn through di resin

M3ace9 · Jun 8, 2015

Getting the TDS down as much as possible before it hits the di stage is key. I go from 240 to 3 going into my DI stage by using 2 spectrapure 99% rejection membranes, 1 0.5 sediment filter, and 2 cloromine filters. From there the 3 TDS water goes into a silicabuster and final di stage.

Shep · Jun 8, 2015

Randy Holmes-Farley said:
FWIW, everyone can get the TDS of tap water down to 0 ppm (measured in line) if they have an appropriate DI resin.

I'd also caution that while interesting to note, tap water TDS is not a measure of whether the water is suitable for a reef. It is just a measure of saltiness of the water. For example, tap water with 5 ppm TDS run through copper pipes might have way to much copper in it, while 300 ppm TDS tap water without such copper (and other undesirables) might be fine.

That said, my tap water has a TDS of about 95 ppm.

But is there anyway to really tell what all is in your tap water?