Acceptable TDS reading ?

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Drummer

Member
Joined
Feb 27, 2004
Messages
23
Location
Spokane, WA
What is an acceptable TDS reading for my water? I installed a new 6 stage RO/DI this week. My tap water measures 150ppm and am getting a reading of 13ppm out of the RO/DI.

Is this ok ....or what should it be?

Thanks !
 

mattseattle

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Joined
Jul 15, 2003
Messages
2,694
Location
Seattle, WA
maybe not for Spokane - could be normal. I've seen alot of people on reefcentral that their local water supply is in the 300's or higher. Luckily in Seattle ours is usually around 35.

After the DI cartridge though it should read 0 but if you test it after the membrane it could be higher.

Is it a brand new unit?
 

Drummer

Member
Joined
Feb 27, 2004
Messages
23
Location
Spokane, WA
Yes, it's a brand new Water General - Model: RO6100DINT

The water here in Spokane is pretty hard, so I'm not suprised at the tap reading. I went to the website of the manufacturer and used their calculation table for the water readings. It said that a new RO/DI would have a rejection rate of 90-95%. Acording to their table, I'm getting a 91% rejection rate. But I keep seeing folks reporting 0ppm readings and that's what I would like to get.
I sent the manufacturer an email about this and am waiting to hear what they have to say.

Would my current readings (13ppm) support coral and other inverts?
 

NaH2O

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Jan 25, 2004
Messages
8,568
Drummer, considering some people use tap water for their tanks, I would think you should be able to support some corals and inverts as long as copper isn't one of the elements that is present. You may find some algae growth. On my TDS meter - our "in" water is in the high 300s and the "out" is 0.
 

mattseattle

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Jul 15, 2003
Messages
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Location
Seattle, WA
did you follow the break in procedures as well? because i remember reading somewhere that you should take out the DI cartridge and run about 20 - 30 gallons through just the membrane before reinstalling the DI cartridge.

what is your TDS on the water after the membrane? and how many gallons have you run through the system?

sorry for missing the word 'new' on the original post. i read it quickly so that was my error.
 

ScottT1980

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Jan 19, 2004
Messages
129
Location
Raleigh, NC
Are you measuring the water in a container? Sometimes containers can have residues that will bump up the TDS...

Take er easy
Scott T.
 

MzWeazelle

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Joined
Jan 11, 2004
Messages
169
Location
WA State
Not to change the subject, but while you guys are talking about all this -

I know what RO stands for (I believe), but what do DI and TDS stand for?
 

cdeakle

Well-known member
Joined
Feb 25, 2004
Messages
199
Location
Lynnwood, WA
TDS = Total Dissolved Solids
DI = Deionozed

I second what ScottT1980 said. When I was a newbie I would use the same 5 gallon jugs to fill with RO/DI ouput water as to mix my new water change water in then wondered my my TDS readings were all wackey! LOL
 

NaH2O

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Joined
Jan 25, 2004
Messages
8,568
RO = reverse osmosis
DI = deionized
TDS = total dissolved solids
 

kevinpo

Expert
Joined
Jul 1, 2003
Messages
2,287
Location
Spokane Valley, WA
Spokane uses mostly water from the aquifer (42 miles long) but some of the area has wells that are on basalt which are high in iron and phosphate. Aquifer water varies with the time of year with a low of 145 ppm TDS to a high of 186 ppm TDS. Several of the smaller water co. do not treat the water but pump it directly from the aquifer.

IMO 1 micron particulate and carbon filters are a must for a high performance unit. Also clear canisters are very helpful to see the pre-filter and DI resin change color.

3-6 ppm TDS can be expected from the RO membrane using Spokane water and 0 ppm TDS out of the DI cartridge.

Most RO membranes are shipped with a preservative and need to be flushed for a couple of hours before use. Color changing DI resin cartriges also need to be flushed for 10 min or so before use.

HTH,
Kevin
 

Drummer

Member
Joined
Feb 27, 2004
Messages
23
Location
Spokane, WA
WOW ! Thanks for all the great input and info on this ! I did flush the system with about 20 gal. before testing the water with the TDS meter. Now after about another 30 gals. I'm getting a reading of 3ppm whereas I was getting 11 - 28ppm.

I do wish the filter and sediment canisters were clear on this RO/DI. Being solid white, I can't see the condition of the filters. Maybe that's why it was the price it was.

Anyway, thanks to everyone that has helped with this. I really appreciate the assistance.

Kevin....expect to see me later this week for some seed sand and maybe that big Tonga you showed me Sat..... if you haven't sold it.
 
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