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View Full Version : What's our water situation like?


iairj84
10/28/2007, 02:07 PM
Hey guys I'm shopping for a RO/DI system for mixing saltwater as well as drinking water. I would like however to know what our local (city) water situation is like so I can choose based a little more on that. I know if the quality is horrible I will wanna go with a better unit. I know the TDS number is what most people go by for water quality so I guess I will go by that. If anyone knows that would be great!

shelbiesdaddy
10/28/2007, 03:44 PM
Here is the 2006 Water Report for Chico.

Chico Report (http://www.calwater.com/pdfs/wq/WQ2006/Chico-CH-410002.pdf)

iairj84
10/28/2007, 05:06 PM
Thanks for that Shelbiesdaddy, I wish I knew what to get from that I it's really interesting to see what's in the water but I don't really know what's good or acceptable or what... I guess 10 TDS is what rainwater is at but I wonder what our tap water is at.

EDIT:
I'm sorry they don't use the abreviation.
Thanks again, it looks like 196 is the average so not tooo bad. I will look for my RO/DI unit based on a max of 300

boviac
10/28/2007, 06:18 PM
I think my tap water usually is around 200 TDS give or take. :D So that seems to agree with that report.

The quality of the system doesn't really matter too much as long as you have a physical filter to remove non-dissolved solids and enough carbon to remove chlorine which will destroy a RO membrane. Then just get a gallons per day system that will work for you.

I replace my filters about every year (but then I've moved a lot) and I've replaced the membrane once after two years but that was my fault.

The only real trick is your RO unit should be sized with a flow restrictor that is rated for the output of the membrane. So once you go with a certain flow-rate module, stick with that one. Then the water coming out of the RO unit goes into the DI module and comes out TDS free. If you have TDS in the water out of the DI, it's time to change the DI. If enough people have RO/DI units that's something we can go in on a group buy - replacement DI resin.

I see systems now that come for drinking water that 'polish' the water after the DI with an additional carbon. I think that's silly unless it's going into a storage tank before coming out of the faucet.

I just have my RO/DI in a rubbermaid bin outside and hook it up to a hose connection. Then I run the brine into plants and another storage for gardening for a while, and then once full, let the rest of the brine flow out onto the lawn.

I ended up getting one of those dual TDS meters: one for the output of the RO and one for the output of the DI but you can set it up however. I also have a bypass on the restrictor so I can 'flush' the membrane upon startup/shutdown/ and every few hours of operation. I've been told this helps increase efficency and life of the membrane. You should also know that when it's colder the RO membrane doesn't work as well as it does when it's warm so you'll have a lot more brine.

Wow so they actually sell RO/DI units based upon TDS inlet? I suspect you might be looking at flowrate capacities. But this surely one be the first time I've been wrong.

If you end up paying more than $150ish you're probably looking too deep unless you want something that will serve your family's drinking water needs as well. (ironic, my aquarium has better water than I provide for myself.)

iairj84
10/28/2007, 06:33 PM
Haha thanks boviac... It is pretty ironic that the water we'll put into fish tanks is much cleaner than that we would put into our families bodies.

They don't sell the units based on the TDS inlet but they have different qualities of the R/O units. The higher quality the less TDS they will put out from the R/O membranes. And from everything I've read the DI resins life changes based on how much TDS it must filter. If our local water was really bad (over 500 i guess is concerned higher than what it should be... good enough for drinking though) and I would want better R/O membranes to save on the cost of DI.

Since it's lower I will go with a cheaper unit somewhere in the $100 range and it should be fine for me.. I might get one with a pressure tank for drinking water as I don't really like the taste of the water but that shouldn't add much to price.

kyletech
10/29/2007, 02:50 PM
I have the kit from Costco with the presure tank and it's cool to beable to do top offs without haveing to wait to make water.

iairj84
10/29/2007, 04:58 PM
How much is the kit from costco? I can't remember seeing it.

boviac
11/02/2007, 11:12 AM
If you want a pressure tank, I find it's better buy the whole kit at once. A pressure tank addition may cost as much or more than the original RO/DI setup. Wouldn't recommend the costco one.