Double checking my RPavlis water math

Water analysis, treatment, and mineral recipes for optimum taste and equipment health.

#1: Post by mythwyth »

Just wanted to make sure I've got my math correct for my RPavlis water:

Using Potassium Bicarbonate and ZeroWater (de-ionized)
I want a final concentration of 100mg KHCO3/1L of H2O

So, mix up a 10mg/1L strength concentrate, I opted to do 1.5g KHCO3 dissolved in 150mL H2O ([15mg/1500mL] = [10mg/1000mL])

My machine reservoir is 2.5L, so I just need to add 25mL of my 10:1000 concentrate to arrive at 2.5L of 100mg/1L concentration, right?

What reading should I be looking for on my TDS monitor to know I'm in the ballpark?


#2: Post by tennisman03110 »

There's 1000 mg in a gram. So your concentrate is 10 grams/liter.

If you want .25 grams in 2.5 liters....well then yes that works out to 25 ml of your concentrate into the tank. Assuming you run it dry each time.

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mythwyth (original poster)

#3: Post by mythwyth (original poster) »

Ah! I KNEW something didn't add up! I was notating as though it was 100mg in 1g, so everything looked off by a factor of 10.

Somehow, though, I got the correct concentration despite my units error.

And yeah, I figured it was just easier to pull out my reservoir, dump the small remaining water at the bottom, and refill so it's always being mixed at 25mL in 2.5L
So, not running the tank dry exactly, but always "zeroing out" for refills.

Thank you for checking my numbers :)


#4: Post by tennisman03110 »

I don't know what Zero Water is. However, for my tank machine, I buy gallons of distilled water for $1 each. And add my concentrate to those. Just fill the tank as needed. I only go through 2 gallons per month.

But my tank is much easier to fill when it's in the machine vs. Remove it.

mythwyth (original poster)

#5: Post by mythwyth (original poster) »

ZeroWater is a de-ionizing filtration pitcher. It filters out almost all dissolved minerals and chemicals, so, similar idea as starting with distilled water.

My first machine was kind of a pain to pull the reservoir out, largely because the tubing was loose and draped over into the reservoir; I usually just filled it with a pitcher. But my new machine has the tubing all self-contained in the reservoir, so it's not really any trouble to pull the container out, fill it, and put it back. Especially considering that it will be easier to stay consistent with proper mineral concentrations in water if I'm not mixing two different concentrations when "topping off"

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#6: Post by GC7 »

This is very similar to my routine.

Suggestion - When the tank is low, dump out the remaining water and use this as an excuse to rinse and clean with soap and water. This will eliminate the possibility of bacterial or mold growth that a couple of recent threads have asked about. Preventive maintenance takes a couple of minutes but saves a potential future headache.