Lately it seems they may be treating the water supply of SE Michigan. PO4 in water post RO/DI is @ 10 after all new cartridges! I have had a couple people w/ same issue and was wondering if anyone else is experiencing this.
I have a new membrane, dual DI chambers, 5&1 micron sediment filters, and 1 micron carbon filters coming from BRS.
New RO/DI configuration will be as follows:
1- 5micron sediment
2- 1micron sediment
3- 1micron carbon
4- 75gpd membrane
5&6- DI
Lately it seems they may be treating the water supply of SE Michigan. PO4 in water post RO/DI is @ 10 after all new cartridges! I have had a couple people w/ same issue and was wondering if anyone else is experiencing this.
I have a new membrane, dual DI chambers, 5&1 micron sediment filters, and 1 micron carbon filters coming from BRS.
New RO/DI configuration will be as follows:
1- 5micron sediment
2- 1micron sediment
3- 1micron carbon
4- 75gpd membrane
5&6- DI
Really hope this takes care of the issue
David,number 3 should be smaller then number 2. I actually run two carbons one a 1 mic and the other at 1/2 mic.Using two sediments might be your problem. Also how big is DI cartridge. With your final filter before the membrane that big you are getting allot more waste water then you should be. The dual carbon block will help you get the TDS your looking for. I have several sets if you want to swing by and grab them and see if it helps. You know the #.
David,number 3 should be smaller then number 2. I actually run two carbons one a 1 mic and the other at 1/2 mic.Using two sediments might be your problem. Also how big is DI cartridge. With your final filter before the membrane that big you are getting allot more waste water then you should be. The dual carbon block will help you get the TDS your looking for. I have several sets if you want to swing by and grab them and see if it helps. You know the #.
Thanks Chuck!
Yes, I see your point and I will take you up on your offer.
So I should go:
1micron sediment
.6micron carbon
.5micron carbon
75gpd membrane
DI 1
DI 2
Currently config that is no longer adequate:
5micron sediment
1micron carbon
75gpd membrane
DI
Also chuck would you install Pressure gauge just before membrane, to know true pressure entering membrane
This I why I love this hobby always learning something new
I believe DWSD does add phosphate to their water to prevent corrosion in building plumbing (required to keep you safe from lead and copper that leaches from plumbing if water isn't treated).
Thanks Chuck!
Yes, I see your point and I will take you up on your offer.
So I should go:
1micron sediment
.6micron carbon
.5micron carbon
75gpd membrane
DI 1
DI 2
Currently config that is no longer adequate:
5micron sediment
1micron carbon
75gpd membrane
DI
Also chuck would you install Pressure gauge just before membrane, to know true pressure entering membrane
This I why I love this hobby always learning something new
That is similar to what I do. I am on well tho so TDS in is much higher then your city water. I have a gage tee'd into my membrane inlet to insure booster pump is working correctly.
I always tell RO/DI users to use the smallest micron range sediment filter they can and make sure it is absolute rated versus the less efficient nominal rated.
In my personal system I use a 0.2 micron pleated absolute rated sediment filter, a single 0.5 micron near absolute carbon block them my RO membrane followed by dual DI.
In almost 20 years of RO/DI ownership I have never found need for two carbon blocks and most vendors who still suply them that way have not done their research. Carbon technology and carbon block extrusion and manufactiring has come leaps and bounds in the last decade or two. The old method of dual carbons served two purposes, 1. the first carbon was used as a sacrificial filter to make up for the high micron sediment filter many insist on using and trapped all the things the less expensive sediment filter should be trapping so it is useless at adsorbing chlorine after a short period since all its pores are fouled and 2. Older carbon did not have the adsorptive capacity of modern carbons and many lasted as little as 300 total gallons( 60 gallons treated and 240 gallons waste at the normal 4:1 waste ratio) so they installed two to give you any chlorine removal capacity at all. Even today there is a vast difference in carbon blocks and their lifespans, a 10 micron carbon or GAC can still last as little as 300 to 1,500 total gallons (treated +waste), a 5 micron as little as 3,000 to 6,000 total gallons, 1 micron 9,000 to 12,000 total and 0.6 and 0.5 micron as much as 20,000 gallons with a single carbon block.
Every filter and canister you place in front of the membrane has an associated headloss which reduces the rejection rate or removal efficiency of the RO membrane making the DI work harder to make up for what the membrane misses and driving your cost of operation up.
I have a pressure gauge on the incoming tap water and after the carbon block so I can monitor headloss at a glance and helps me trubleshoot the system more effcetively. I also use a low range chlorine test kit to monitor the effectiveness of my carbon block at removing chlorine.
What are you using to test the phosphates in the finished water? I spent some time with an organic chemist a few days ago and heard some doubts expressed about the Hanna Checker instrument. For one, it is extremely hard to test ultrapure waters with any degree of accuracy and repeatability. Think about it, we are talking about parts per million or parts per billion here. To put that in perspective 1 ppm is like 1 penny in $10,000, 1 minute in 1.9 years, 1 inch in 15.8 miles or 1 ounce in approximately 32 tons. It is miniscule! A ppb is like 3 seconds out of an entire century. We are asking a small handheld hobbyist instrument to measure something that small and we are not in a controlled environemnt like a clean room or lab using sterilized instrumentation and apparatus and expecting accuracy down to these levels? I don't think so!
Even one hard water deposit or grain of dust in the glass you use to test in or your test tube will skew the results dramatically. Take the same test 10 times in a row and the results can be all over the place unless you do things in exactly the same way every time, use the same glass washed and rinsed the same every time, draw the same exact amount of sample each time with a titrator or let it mix or sit for exactlty the same amount of seconds etc. Hobbyist grade instruments can get you in trouble when you are depending on lab grade results and personally I don't lend much credence to them. I look at them more like a presence absence or litmus paper test, you have phosphates at a measurable level or you don't.
If you do suspect phosphates in your RO/DI water I would look at two things first, improving the rejection rate or removal efficiency of your RO membrane since it removes 90-98% of the contaminants and improving your DI resin and/or bed contact time in the DI canister(s) to get maximum treatment. The sediment can carbon filters have little effect if any of contaminants such as phosphates or TDS in general but they are important for protecting the RO membrane and ultimately the DI filter. Another thing you can do is to install a water softener if you do not already use softened water as this takes a huge load off the RO membrane.
You nailed it by critiquing the accuracy of phosphate testing. Organic phosphate is everywhere and touching the inside of your testing equipment can introduce error into your measurements. If your testing equipments comes with a positive and or negative control solutions, then by all means use them. The best indirect measure of phosphate in any artificial reef system is the presence and relative abundance cyanobacteria in your tank. If you have positive cyanobacteria growth, then you have elevated phosphate. Municipal water supplies use phosphate as a way of removing iron from drinking water......................................Jim
Thank you for the input I test w/ Hannah Low Range Meter, agreed Checkers are junk. . I thoroughly clean vials in alcohol and store clean and dry in a dedicated plastic container. My testing procedure has remained consistent for more than 6yrs w/ repeatable results (I always run 2 different samples). No change in feedings or dosing, the only change was the recent nasty colored cold water which i believe shot my RO/DI PO4 from .00 to .08 and PPM from 0 up to 8ppm (keep in mind the values have been stable over 2 yrs) that being said my primary concern is not the presence of PO4 or precise value but the huge rapid jump in PO4 levels
I did not know the Nom vs Absol ratings for the filter cartridges! Can you recommend a good supplier? This may explain why this batch of filters did not last long (4-6wks)
I know Spectrapure sediment filters are absolute rated and I believe Buckeye Field Supply also carries them too. I still say if you are getting phosphates in your finished water you need to be looking at your RO membrane and both the resin and residence or contact time in your DI filter since those are the two pieces that remove the phosphates. Some membranes are better than others and some resins are better than others at removing certain things. The sediment and carbon filters only protect the RO membrane and do not remove much by themselves other than particulates and chlorine.
SE Mich check your RO/DI for PO4
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Originally Posted by dknuckles
