Okay, so along with
@Sisterlimonpot we both spent the better part of the day with
@SpectraPureInc. We have been working together and alongside them to get our RO/DI systems tuned to get the max performance out of them. Let me tell you something, their shop is literally a chemistry lab for water. It's not just a random shop that puts together parts that they order wholesale. They have multiple test benches, spectrophotometers and other devices that I have no idea what they're called. These guys study every single possible part of water and what could be in water and develop in house solutions to deal with your specific water.
While we were there we received a crash course on how RO/DI systems work and it is actually is a more involved process than one would think. The biggest thing we learned I would say that 0ppm TDS water isn't always contaminant free. The 0ppm TDS can actually read from 2.21in EC all the way down to 0.000 in EC , for reference 0.001ppm of TDS will still read a 0.057 in EC.
Secondly we learned the importance that softened water plays in making RO/DI. To be an NSF certified membrane they need to be tested with a softened water value 250ppm TDS. That along with 60 P.S.I and 76F water temperature is where they calculate the standard rejection rate of the membranes.
I started my hobby with planted tanks and I am big on freshwater shrimp. The kinds of shrimp I have require a certain General Hardness level to be able to develop their exoskeletons and molt properly. Anything over 8 degrees of GH and you are going to start having dead shrimp due to failed molts. I did what anyone wanting to keep shrimp would do and check my GH from tap, the lowest reading I ever received was 26 degrees (463ppm). That's a lot of Calcium and Magnesium to be throwing into your RO system. Imagine getting all that hard water build up you see around your sinks and faucets but inside your RO system clogging up your filters, lines, fittings and membranes.
I live in an apartment so I do not have the luxury of installing a water softener in my home so I asked about what options they had. They then showed us a specially formulated resin that they have to use in-line before your RO pre-filters to soften the water. I was extremely doubtful that this 10x3 canister could make any dent in my water hardness but it was affordable enough to give it a shot.
Here is what it looks like:
So here came the fun part, the very first thing I did was run my RO system without the water Softener to get a baseline performance of my Unit. After 5 gallons of RO these were my numbers (Note this is not DI numbers only RO)
Its hard to read but input was 709 ppm
output was 8 ppm:
Next up was to install the water softener and test the input and output again and here are the results.
791ppm In:
4ppm out:
So with just the addition of the water softner I went from a rejection rate of 98.9% to 99.5%. That $30 water softener investment already paid for itself as it just doubled my DI's Capacity.
The next step was to test the GH of the tap water and the GH of the softened water. I disconnected the line from the water softener that goes to the RO unit and filled a container that had been pre rinsed with 0ppm RO/DI water to avoid any contamination.
To test the water samples clean RODI rinsed glasses were used to avoid as much contamination as possible and new never before used pipettes where used. I tested with GH test strips and the API GH test and here are my findings.
The API GH test is supposed to turn the water orange when calcium and magnesium are present and then drop by drop you count until the test turns green. You count the number of drops and that gives you your GH level. The test strips are to be put in the water for 3 seconds and then let stand for 20 seconds before you take the reading.
Tap water (Right glass and tests) came in at 36 degrees of general hardness or 631ppm which you can see that the test strip also gave a high reading.
Softened water (Left glass and tests) came in undetectable. From the very first drop the water did not turn orange. instead it was a very light green, almost yellowish due to the dilution levels. To verify I added drop by drop and all it did was turn more green and never once turned orange. I stopped trying after 10 drops. The test strip also was a light color that wasn't represented on the chart when comparing it to the legend.
Here are those pictures to get a look at my results.
So the question comes, should a water softener be used when making RO/DI the answer for me is always. Now with my GH tap level I don't know how long my resin will work before being expended. For that I am using a volumizer that counts the amount of gallons of water that pass through to gauge just how long I can go without needing to change it. I plan on testing my water's GH every 50 gallons to ensure I am still getting use out of the resin.
Heres a picture of my RO/DI set up for those of you who would like to see it.
What else did I hear out there....pop and grinders for soda and a sub sandwiches....and the tailgate at Brewer's stadium had to include Brats cooked in beer....but my favorite, and what I miss is Kopps Ice cream in Milwaukee (Glendale)....not far from my place in Brown Deer.
