DI Water Quality Curve??

I pretty much have my old DI water problems solved, but now (of course)I have new problems: I was monitoring the degradation of water quality to see how long it would take to get down to 2.05 Megohms (is this too high to change the tanks?-it's pretty much an arbitrary setting) and noticed that it will get down to about 10 M/ohms and stop; later it will suddenly be <2.05 and the sirens will go off! I can monitor the No. of gallons used, but I am bothered by not knowing the degradation curve. I'm pretty new at this-can you tell? I would greatly appreciate any info on how the water quality should typically degrade. Also, the flometer in my Electrovert H-400 wash supposedly does *not* require calibration. But I am suspicious of it. Has anyone had a problem with this gauge before? I'm still looking for a stainless heater.

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| I pretty much have my old DI water problems solved, | but now (of course)I have new problems: | I was monitoring the degradation of water quality to | see how long it would take to get down to 2.05 Megohms | (is this too high to change the tanks?-it's pretty much | an arbitrary setting) and noticed that it will get down | to about 10 M/ohms and stop; later it will suddenly be | <2.05 and the sirens will go off! I can monitor the No. | of gallons used, but I am bothered by not knowing the | degradation curve. I'm pretty new at this-can you tell? | I would greatly appreciate any info on how the water | quality should typically degrade. | Also, the flometer in my Electrovert H-400 wash supposedly | does *not* require calibration. But I am suspicious of it. | Has anyone had a problem with this gauge before? | I'm still looking for a stainless heater. SMD: SS water heaters come in two varieties. Dave F 1 Flash heaters supplied by: Process Technology 800.621.1998 Exton 800.234.2781 804.978.4335 fax4935 extron@mail.rlc.net 2 Tank heaters supplied by: Winokur Water Systems 800.234.2781 fax804.978.4935 AOSmith 800.527.1953

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| I pretty much have my old DI water problems solved, | but now (of course)I have new problems: | I was monitoring the degradation of water quality to | see how long it would take to get down to 2.05 Megohms | (is this too high to change the tanks?-it's pretty much | an arbitrary setting) and noticed that it will get down | to about 10 M/ohms and stop; later it will suddenly be | <2.05 and the sirens will go off! I can monitor the No. | of gallons used, but I am bothered by not knowing the | degradation curve. I'm pretty new at this-can you tell? | I would greatly appreciate any info on how the water | quality should typically degrade. | Also, the flometer in my Electrovert H-400 wash supposedly | does *not* require calibration. But I am suspicious of it. | Has anyone had a problem with this gauge before? | I'm still looking for a stainless heater. We use Elga cylinders to di-ionise our water. I do not know the decay rate, but they might. Remember the rate will be depandant upon the through put & our cylinders are affected by temperature, so make sure the water is below 70oC. Elga e-mail is elga@elga.demon.co.uk - give them a try. We also use a Purite meter to measure resistance. We change at 0.5 micro semens/cm2 Which is about 2Mohms. We calibrate the meter every year. Hope this helps, even a little.

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Your experience is typical. The degradation curve of resins resembles the track of a Six-Flags roller coaster. Water quality remains high (10 MW+) for 80% of the resin's life. For a very short time, quality will drop to 7 - 8 MW, then, without notice, your water quality will plunge to less than 1 MW. The best analogy is to NiCad batteries. They stay at "full charge" for a long time, then, when you need them most, they crash. This is normal. You can determine (within a very close proximity) the resin life by obtaining the resin's grain capacity (its ability to "absorb" contaminants). Your resin dealer will have this information. Determine your tap water's PPM or TDS (your water supplier will publish this). Take the tap water's TDS or PPM and divide it by 17.1. This is your grains per gallon. Divide the resin's grain capacity by the tap water's grains per gallon and the result is the number of gallons your resins will last before they are fully spent. If you need more information, you may call me at (800) 218-8128. Mike Konrad

| I pretty much have my old DI water problems solved, | but now (of course)I have new problems: | I was monitoring the degradation of water quality to | see how long it would take to get down to 2.05 Megohms | (is this too high to change the tanks?-it's pretty much | an arbitrary setting) and noticed that it will get down | to about 10 M/ohms and stop; later it will suddenly be | <2.05 and the sirens will go off! I can monitor the No. | of gallons used, but I am bothered by not knowing the | degradation curve. I'm pretty new at this-can you tell? | I would greatly appreciate any info on how the water | quality should typically degrade. | Also, the flometer in my Electrovert H-400 wash supposedly | does *not* require calibration. But I am suspicious of it. | Has anyone had a problem with this gauge before? | I'm still looking for a stainless heater.

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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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: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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