wow your lucky!!! So do you have like a frankenstein rod unit?
RO/DI and TDS readings
- Thread starter woochi
- Start date
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Nice setup I'll show you mine tomorrow
Trex
Valuable Member
I would not hook it up to any hot water source, even with the plans of mixing it. Hot water will ruin the RO membrane.
Why are you using so many carbon blocks?
How do you know that you are going through DI resin so fast? I wouldn't go by the color change, just go by your TDS meter.
Why are you using so many carbon blocks?
How do you know that you are going through DI resin so fast? I wouldn't go by the color change, just go by your TDS meter.
Never ever, I repeat, never blend hot and cold or temper the water temperature!!!
remember being in the shower and someone flushed the toilet or started the washer? You got your tush scalded. The same things happens to an RO membrane and they cannot take anything over 113 degrees or they melt. Besides colder water treats better than warmer water and will give you lower RO only TDS and longer DI life since it is less viscous.
Sediment and carbon filters have very little to absolutely nothing to do with TDS, I have posted this hundreds if not thousands of times on all the reef forums. Their purpose is to protect the RO membrane from TSS or Suspended Solids, big floaty stuff like silt, sediment, particulates and colloidal materials. These are things you can see in the say 1 micron and larger sizes. TDS or Dissolved Solids are just that, dissolved, and are in the 0.001 micron range, hindreds or thousands of times smaller than either filter can remove. The RO membrane is the workhorse and removes 90-98+% of the TDS and the DI does the final polishing off of that last 2-10% so they must be well protected.
By adding all those stages in front of the RO you have actually made things much worse, not better. Each filter, housing and fitting has an associated headloss or pressure drop which reduces the RO rejection rate or removal efficiency. You want One sediment filter in the 0.2, 0.3, 0.5 or no larger than 1.0 micron range. One, no more, One 0.5 or 0.6 solid extruded carbon block, the RO membrane and either one or two DI filters. Thats it, no more and no less.
I see another big issue in your sketch. You need a check valve after the tee feeding the DI filters so you isolate the RO pressure tank and faucet from the DI. When you do this you make DI directly from the RO membrane and not from the stored TDS creep water in the presure tank which eats DI much quicker since each time the RO kicks on to satisfy the pressure in the tank it sends a spurt of TDS creep water so it eventually can get as high a TDS in the tank as the tap water.
Take a look at the check valve placement in this diagram:
http://spectrapure.com/huds/4-STAGE-DWK-RODI-NAG.pdf
remember being in the shower and someone flushed the toilet or started the washer? You got your tush scalded. The same things happens to an RO membrane and they cannot take anything over 113 degrees or they melt. Besides colder water treats better than warmer water and will give you lower RO only TDS and longer DI life since it is less viscous.
Sediment and carbon filters have very little to absolutely nothing to do with TDS, I have posted this hundreds if not thousands of times on all the reef forums. Their purpose is to protect the RO membrane from TSS or Suspended Solids, big floaty stuff like silt, sediment, particulates and colloidal materials. These are things you can see in the say 1 micron and larger sizes. TDS or Dissolved Solids are just that, dissolved, and are in the 0.001 micron range, hindreds or thousands of times smaller than either filter can remove. The RO membrane is the workhorse and removes 90-98+% of the TDS and the DI does the final polishing off of that last 2-10% so they must be well protected.
By adding all those stages in front of the RO you have actually made things much worse, not better. Each filter, housing and fitting has an associated headloss or pressure drop which reduces the RO rejection rate or removal efficiency. You want One sediment filter in the 0.2, 0.3, 0.5 or no larger than 1.0 micron range. One, no more, One 0.5 or 0.6 solid extruded carbon block, the RO membrane and either one or two DI filters. Thats it, no more and no less.
I see another big issue in your sketch. You need a check valve after the tee feeding the DI filters so you isolate the RO pressure tank and faucet from the DI. When you do this you make DI directly from the RO membrane and not from the stored TDS creep water in the presure tank which eats DI much quicker since each time the RO kicks on to satisfy the pressure in the tank it sends a spurt of TDS creep water so it eventually can get as high a TDS in the tank as the tap water.
Take a look at the check valve placement in this diagram:
http://spectrapure.com/huds/4-STAGE-DWK-RODI-NAG.pdf
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so it's ok if I run my unit below 78? What's the lowest temp that is recommended? I was just going by my ro intrusions which said 78
77 degrees F or more accurately 25 degrees C is just a number the industry picked out of thin air to test one manufacturers membrane against another. It is not the point where they work best, far from it in fact. The colder the better as far as water quality goes, the only disadvantage is it cuts the GPD. No big deal if you have a 75 GPD membrane and can store water made over time or you can do as I did and install a RO booster pump which further improves both the rejection rate(removal efficiency) and the GPD. Membranes can operate up to around 150+ psi and get extremely efficient at those higher pressures. My tap TDS is around 560 and my RO only TDS is between 2 and 3 always but I run my booster at 95-100 psi and have a single 0.2 micron pleated absolute rated sediment filter and a single 0.5 micron 20,000 gallon carbon block in front of my RO so almost no headloss since the 0.2 micron filter has 10x the surface area of a normal sediment filter..
Remove all those filters and carbons in front of the membrane and see how much your pressure rises and your RO only TDS goes down. One of each as long as they are 1 micron or smaller, high quality and not ebay stuff. No granular carbons either except one on the drinking water faucet for taste and odor control.
Your DI will thank you for sure.
Your DI will thank you for sure.
Thanks for the info on cooler water will be doing that for now on
The folks at Spectrapure are Pro's and have been doing RO/DI for over 25 years in the same AZ city. They were doing RO before most people even heard of it. Take a look at the FAQ section at the bottom of their web page for a ton of good information.
If you have had coffee from that famous place everyone frequents you have probably had their RO/DI then remineralized to be perfect water and didn't even know it!
If you have had coffee from that famous place everyone frequents you have probably had their RO/DI then remineralized to be perfect water and didn't even know it!
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fletch999
Well-Known Member
"After all that my tds is still 130. The membrane removal is 128 tds and the di stages clear the rest. Are these readings normal?" This not normal your membrane should bring it to 2-10 TDS, Did you just replace your membrane and not get it installed properly? If not how old is it? It does not seem to be working properly.
I think you misunderstood.Looking at the sketch in the first post they note the RO only TDS is 2. The 130 is both before and after the sediment and carbon filters which is as it should be.
