Hello,

Since 2006 I have been using Crystal Geyser bottled water from one of the spring sources that has not-very-hard water (high 20s). Now all of a sudden the Crystal Geyser water available where I live is coming in from their newest spring, which has hard water (about 170). My tap water is 400+.

I have read on many threads here and elsewhere that some people use a RO system and then add a calcite filter to put some minerals back in so that the water isn't too low in mineral content, both to activate the boiler's sensor and evidently also so that metals aren't leached inside the machine (copper).

My question is: Can't I just put a little tap water in the RO water to achieve the minimum necessary minerals? Without adding the extra step of a calcite filter? I have seen the calcite filter suggestion many places but never with the explanation of why that instead of just dumping a little tap water in.

I have a digital TDS meter so could measure a mixture to see what sort of TDS I'm putting in.

I already have been adding a couple ounces of tap water to the bottled water in my reservoir, achieving a TDS of about 50.

I realize I could get really into this to make my coffee taste even better, but right now my goal is to just continue not destroying my machine with scale.

Thanks for any insight you can provide.

I have been doing almost exactly what you describe for several years. The only difference is that I mix tap water with some local spring water which has very, very low hardness. For these purposes it is essentially equivalent to RO (in fact I have suspicions that that is exactly what it is, just put in a different bottle )

I used an inexpensive aquarium test kit and Jim's Insanely Long Water FAQ to determine the mix of tap water and RO/spring water I wanted. I marked a line on a plastic gallon jug (around 1/10 to 1/8 gallon) and fill up to the line with tap water, the rest with RO/spring.

Works for me.

Jim

Hi,

Thanks for the info! I appreciate it. I think this is what I'm going to do.

Have you ever descaled your machine? I never have, which seems kind of crazy since I've had it almost 8 years, but it still seems to be working fine. The distributor of my machine said it's not something I should do on my own, so I'm considering finding a place to take it to just for the heck of it.

Thanks,

Meredith

I descaled a few times using CleanCaf before switching over to the magic water mix. But I have not descaled since then.

Jim

I do something similar in that I buy RO water in 5 gallon bottles for my water cooler and mix hot RO water with about 10% filtered tap water. I did some testing and this seems to work out to adding some minerals without producing scale in my BraZen or my lever espresso machines.

I think the calcite filter is more convenient for people who plumb their espresso machines in to a pressurized water line and don't have a filter system with a bypass valve.

I've been using straight plumbed in RO+DI for 12 years and never descaled or had a leak. I've also never had a better espresso than what I pull myself. YMMV of course.

In addition to the DI for my appliances, i have a significant filtration system for my house that includes a calcite filter to help raise the pH of my water. To my knowledge calcite will only add hardness if your water is acidic, otherwise it won't dissolve.

If you really want to add hardness, you might look into Burton water salts used by homebrewers.

I realize I could get really into this to make my coffee taste even better, . . .

Maybe. But in any event, your attitude is to be applauded.

To get as close to the SCAA water standards without a lot of work, pick up some "Gerber Pure" water from your local CVS. When it is not on sale, it is about $1.80/gallon. Try it and see if you can discern any difference. It is not as friendly to your machine as your current practice but SHOULD produce a better tasting beverage.

Here is something you should do with your machine - Checking an E61 Espresso Machine for Scale . It is easy to do and reaps dividends in confidence building.

Reverse osmosis should not be mixed with tap water. This defeats the purpose of having RO water in the first plane, as you are just re-introducing toxins and chemicals back into you filtered water. If you want to add some hardness to the reverse osmosis water, you can add salts, or get a re-mineralization stage to go on the end of your reverse osmosis system. But by adding tap water, you are simply adding chlorine and other chemicals, in which cannot compare to the taste you can get with filtered water from a reverse osmosis system.

therabidweasel wrote:I've been using straight plumbed in RO+DI for 12 years and never descaled or had a leak. ....

OK I'm gathering that DI is deionized water? Is that something you deionize with a system of some sort or something you buy in a bottle?

AdamM wrote:Reverse osmosis should not be mixed with tap water. This defeats the purpose of having RO water in the first plane, as you are just re-introducing toxins and chemicals back into you filtered water. If you want to add some hardness ...

The reason I was adding tap water (and I have also been testing shots using a mix of RO and different bottled spring waters that also happen to be hard) is that I can't put my tap water in my machine, our city tap water is 470 ppm TDS. That would eventually harm the boiler.

It seems that perhaps we should look at installing a RO system with a filter on it (calcite?) to reintroduce minerals back into it? I guess I'm not focusing on whether I am ingesting toxins and chemicals at this point (sorry) I'm just trying to a) get a shot that tastes good and b) not ruin the machine. The shots mixed with RO water did not taste good. However, had it been RO with a calcite filter might they have tasted good? UGH this makes me just want to not own an espresso machine anymore.

AdamM wrote:Reverse osmosis should not be mixed with tap water. This defeats the purpose of having RO water in the first place, as you are just re-introducing toxins and chemicals back into you filtered water.

Oh please. Exactly which toxins and chemicals are you concerned about?