:Steve, If you want to get a constant flow of higher quality water to supply to your cleaner, you could install a fliter, carbon filter, softener, and an Reverse Osmosis unit that dumps to a storage tank and draw from that. This will give you a constant supply of 2.1 to 2.3 mg/L TDS water. Here in NY water is not that expensive, and since we cannot recycle our water due to the high use of solder masks, this provided the highest water quality at resonable costs. Hope this is helpful! Steve
Hello there, | I've been reading these posts with a little interest as I'm just setting up a contract assembly facility here in Sunnyvale, California. I've learned a few things concerning water quality & filtering bed life that I thought I'd share with ya'll... | I just started here last month, and almost all of the equipment was purchased before I started. There was a Trek Triton IV purchased for the facility here, and included a onboard closed-loop ion exchange treatment system. | Well, the owner was told that there wouldn't be a requirement for an external DI system for the make-up water that the machine loses during normal operation (anywhere from 3-10 gallons per hour), as the onboard system will take care of that. I didn't think that was a very good thing to tell the owner unless they knew for sure how good the water is out here. | I did some checking on things, and was pretty suprized at what I found out, and this may apply to ya'll that have questions about DI water quality curves and filtering bed life. | Now what I'm about to talk about applies out here in Sunnyvale, California, but could apply to wherever you're at. | First thing I learned was that you can't count on the quality of the tap water out here. We get our water from 3-sources; | 1. From the San Francisco Water Department which gets it from the Hetch Hetchy Resevior in the Sierra's | 2. The Santa Clara Valley Water District which gets their water from the Rinconada Water Treament Plant | 3. Sunnyvale well water. | Of the three, the water from Hetch Hetchy is the best as far as hardness goes...but still it's not all that great. There's a gentleman that I spoke with at a company called Pacific Water Systems out here named Peter Forrest. He and I got into a very good discussion about the water quality here in the bay area. By the way, Pacific Water Systems is who I'll be doing my bed exchanges with. | Peter told me something I never knew before. He learned a while back that the Hetch Hetchy water supply is shut down once a year for maintenance of the water lines, this is usually done sometime between Novemeber and March. It may only last 2-weeks, or may last 2-months, it just depends on how much work needs to be done. | So during those months that Hetch Hetchy is shut down, we're being supplied the "crappy water" so to speak, that is much harder than the water from Hetch Hetchy. This of course will reduce the life of my mixed-beds. | Peter says he can usually tell when the water has been switched because he'll start getting more calls than normal for DI bed exchanges, and he sometimes gets calls from customers that complain that Pacific Water has given them bad mixed beds because they didn't last as long as the beds that they had in earlier. So he needs to try and explain why the beds are being used up so quickly. | He also gave me a number that I could call and get a water quality report from the city of Sunnyvale which lists levels of contaminates in all sources of water that is supplied by the city. | I requested the report, received and read it, and to put things bluntly, I'm screwed. Not only do they switch water sources, but they BLEND it! Here's a paragraph out of the report: | " The different sources of water blend throughout the Sunnyvale water system, and the proportion of the mix varies from day to day and season to season depending on demand, operatioal requirements, and costs of purchased water." | In short, I won't know what quality of water I'm getting. The only way I'll be able to tell is by how often I change my DI beds...fun huh? | Here's the listing of water hardness in PPM for each source: | 1. Hetch Hetchy - ranges from 14-66 ppm | 2. Rinconanda - ranges from 75-129 ppm | 3. Wells - ranges from 250-360 ppm | Quite a variety huh? So I could be getting 14 ppm water one day, and 360 ppm water the next. | So to sum this "little note" (hehehe) up, it's worth it to find out for sure what kind of water you're getting and if it stays on one source during the year. This stuff I'm dealing with I imagine, mostly occurs out here in California where water normally is pretty hard to come by (except during El Nino season!). But it's still a good idea to check and make sure...otherwise what is just a change of water sources could be interpretted as a problem with your system. | Have a great weekend everybody! | -Steve Gregory- | |
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