View Full Version : Purity Monitor
10/20/2005, 07:32 PM
Hello, I just purchased your Deluxe CSP-DI 90gpd unit. I ordered it from Premium Aquatics and you shipped it. Problem is you were out of the monitors and PA agreed to send me one instead. The one they sent me was not the same as you use. I would like to know when I could get one from Spectrapure. The one I received seems very cheap. This is my first RO/DI unit and I wanted the best so I bought your product. Thanks, Adam
10/21/2005, 03:17 PM
We will be out of the Purity Monitors for a while. We are sending systems out without them for the interim. We will send you a monitor when we can get them. Keep track of the gallons processed by the DI cart. Call us when you get to 400 gallons. We will talk about alternatives at that time.
I'm curious, please describe the monitor you were sent by PA.
10/21/2005, 05:28 PM
10/21/2005, 05:28 PM
please see next post:rolleye1:
10/21/2005, 05:29 PM
I actually checked your website and the one they sent me was the Dual inline TDS meter, the same as on your website. I thought you needed the push to test type with the switches. If this is just as good or better I will go with it. I have another question. Is there any downside to lengthening the hoses on the unit? Say I go to Home Depot and buy longer hoses and replace the ones on the unit. Will there be any problems? Is the yellow hose the waste line? I have no experience setting up a RO/DI unit so I'm learning as I go. Thanks for your help, Adam
10/22/2005, 04:53 PM
That is actually a very good and handy meter. To its credit, you can monitor two different points in the production stream with real TDS (Total Disolved Solids) numbers. It is usually used to monitor the performance of the RO membrane's "Rejection Ratio" which, for our membranes is usually about 98%. This means that for every 100 ppm TDS in the tap water entering the membrane, only about 2 ppm TDS will leave the membrane. So, if the "IN" probe is installed in the black feed water line and the "OUT" probe is in the blue product water line, you can monitor these two values and do the math. Be sure to line up the dots.
If you find your tap water TDS is pretty constant (it isn't where we are), you can move the "IN" probe to the blue product water line leaving the membrane (before the DI) and put the "OUT" probe in the DI water line so you can watch the membrane output and the DI output.
The DI output should always read "0 TDS". But, 0 TDS does not mean "no TDS". Our laboratory customers are concerned with parts per BILLION. But, the equipment used to accurately measure these very small concentrations is extremely expensive.
The Dual TDS Monitor seems to be pretty reliable discerning between 0 TDS and 1 TDS. The DI Purity Monitor has a pre-set green/red "trip-point" (on switch #7) of 0.67 ppm TDS. Also note that "Switch #6" jumps to 1.3 ppm TDS. Not much in terms of resolution.
When the DI water quality "drops" to only 1 TDS, we find that this level may actually be beyond the start of "silica-breakthrough". Silica is not as readily detected by "TDS meters", so if silica and ditomes are of particular concern to you, this may be a difference to be considered.
You should have, by now, read about adjusting the flow restrictor to obtain the ideal 4:1 ratio of waste (or brine or concentrate) to good (or product or permeate).
Distances within the typical house should not be a problem. One guy tried to run his waste line about 100 yards to his well head in hopes of returning it to ground. That much length did present an abnormally large restriction to the flow of the waste water and prematurely plugged up his membrane.
The much more common mistake comes when one replaces the yellow waste line with a longer one and throws away the flow restrictor!
Tap water is first filtered by mechanical means to remove dirt and other non-disolved solids. Carbon then neutralizes the chlorine that can damage the RO membrane. Then, under pressure, pure water molecules pass through the ultra-small-pore membrane material. The flow restrictor regulates the flow of the remaining TDS-rich water to the drain.
We are here to help and appreciate your interest in us.
10/22/2005, 07:25 PM
Wow! Thanks that helps alot, Adam
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