What's the TDS of your tap water?

[FRITZ]

Sunny San Diego California beautiful place but the tap water, sucks!! 452 going in and 0 coming out and I burn through DI. And the Chloramines are off the charts.

 

[fishtankpete]

Cornwall UK 67 in 0 out

 

[Lee Haynes]

I'm from Swindon, England and I get 340 in and 0 out. I use a lot of di mixture but I make pure water for my window cleaning company so the business pays for it

 

[markalex]

350 ish here near london

 

[chrisfraser05]

Montrose in Scotland.

Consistently 39 in, 0 before di pod

 

[chris.scangarello]

TDS from the my tap is 168 in Valrico, FL. but 0 out after the DI stage.

 

[greg 45]

Going to put this out there. I don't know why we use this number 0 as a good number after the last chamber of the ro/di system. My phosphates read well over 2 coming into house , I can get 0 tds and still have phosphates and nitrates with this magical number. I recommend everyone check the make up water after it's made to see there isn't any inpurities left after making water. Yes I run 3 chambers of di high grade resin.

 

[psirex]

The units are not built toremove those components from the water........

Albany, NY

240
0

 

[NanaReefer]

165 from our Trailer Park treated well water [emoji2]

 

[Randy Holmes-Farley]

Going to put this out there. I don't know why we use this number 0 as a good number after the last chamber of the ro/di system. My phosphates read well over 2 coming into house , I can get 0 tds and still have phosphates and nitrates with this magical number. I recommend everyone check the make up water after it's made to see there isn't any inpurities left after making water. Yes I run 3 chambers of di high grade resin.

The reason we use it is that it is a very good way to evaluate if an RO/DI is working properly.

If yours really is 0 ppm TDS, the amount of phosphate and nitrate coming out of it will be low enough to be totally unimportant relative to other inputs to your aquarium. Foods for example.

Here's a blurb from one of my articles explaining this:

http://www.advancedaquarist.com/2012/3/chemistry

from it:

Comparison of Food Sources of Phosphate to Other Sources
What about other sources of phosphate, like the "crappy" RO/DI water containing 0.05 ppm phosphate? A similar analysis will show it equally unimportant relative to foods.

Let's assume that the aquarist in question adds 1% of the total tank volume each day with RO/DI to replace evaporation. Simple math shows that the 0.05 ppm in the RO/DI becomes 0.0005 ppm added each day to the phosphate concentration in the aquarium. That dilution step is critical, taking a scary number like 0.05 ppm down to an almost meaningless 0.0005 ppm daily addition. Since that 0.0005 ppm is 40-600 times lower than the amount added each day in foods (Table 4), it does not seem worthy of the angst many aquarists put on such measurements. That said, tap water could have as much as 5 ppm phosphate, and that value could then become a dominating source of phosphate and would be quite problematic. Purifying tap water is important for this and many other reasons.

 

[psirex]

^ I stand corrected ^

 

[Reeftech]

Waterford, MI 280-300 tds going into filter. 4 coming out of membrane and triple zeros coming out of di chamber.

 

[KillKennyTank]

I live in Tampa, FL. Coming out of the tap, my TDS is 155 and 0 out of ro/di filter.

 

[Longnose Hawkfish]

Tap 70-80,
After RO/DI 0

 

[spllbnd2]

35 TDS from the tap in Edmonds Washington.

 

[wangspeed]

About 120 in prince William county VA

 

[mkj]

Vancouver BC
Tap TDS : 3-5. never seen it above 5
RODI output: 0
We have the best water in the world though and a very modern Hydro system. Tap water is cleaner than bottle water but I still use RODI for the last bit. the filters last a very long time.

 

[gramps]

london south east, tds out of tap 260/290. into 0,5 micron sedi then carbon block and another 0.5 particle filter, then into 1st membrane (150 gallons a day rated) then into 2nd membrane (same as first) and finally into rodi unit 1 litre resin and a reading of 0.

 

[AZDesertRat]

As Randy mentioned in Post #8, any RO/DI should be capable of 0 TDS effluent. The important number is the RO only TDS. If your RO membrane is not efficient you could be using much more DI resin than necessary since it is acting as a crutch to prop up a poorly performing RO membrane.

Last I checked mine it was 630 softened tap TDS, 3 RO only TDS and 0 from each of my dual DI filters. The 3 TDS means my RO membrane is extremely efficient at better than 99% rejection rate so my DI lasts a long long time. My previous membrane was only capable of taking that 630 down to between 13 and 15 which was still respectable but DI at that time only lasted 150 measured gallons per 20 oz cartridge. Check your RO only TDS on a regular basis and you may save yourself money by replacing the RO membrane rather than more frequent DI replacements.

 

[Hurricane Aquatics]

45-50 in Winston Salem, NC