Budget RO system

erkal

Question: What PPM are you meant to read from the water coming out of the grouphead? I know it reads higher when hot but what PPM are we aiming for when cooled?

MWJB

erkal You’re not aiming for a cooled ppm, that can vary depending on conditions in the boiler. What is the ppm of the water being fed to the boiler?

Adrianmsmith

erkal
As per mwjb

But also ppm is not everything and can have different values depending what chemistry you are aiming for, what remineralistion you are using.

Ppm on its own is virtually meaningless without knowing what the makes up to p

erkal

MWJB It’s around 120ppm. How much should it be?

erkal

Adrianmsmith I found some recipes and have been experimenting so I am still trying to figure it out.

MWJB

erkal What are you adding to it? (Sodium bicarbonate etc.?)

erkal

MWJB magnesium sulphate, calcium chloride, potassium bicarbonate

MWJB

erkal So how much are you adding? If you’re adding stuff, you should know how much you are putting in there.

erkal

MWJB

I used this guide to make the concentrates and then used the following recipe to make 2.5lt water

Epsom Salts 15ml

Calcium chloride 7.5ml

Potassium Bicarbonate 5ml

MWJB

erkal It’s not clear to me when they are talking about ppm as ion, or as CaCO3.

If you made the concentrates at the proportions on the website (which I’m not sure can be trusted), you have added about half a gram of the ingredients to your 2.5L, or just over 200ppm in raw materials.

Your TDS meter does not read values as CaCO3.

If you can be more specific about exactly what you did, that may help.

Bear in mind that your house receives a handy source of mineralised water every day, that you can use, very simply to adjust your RO water.

erkal

MWJB So yesterday I made the concentrates exactly as explained on that guide I posted. I then used the recipe I mentioned and filled my tank. If you want to know exactly how much went into the tank then AI says its roughly around these numbers:

Epsom salt 15 mL - 369 mg

Calcium chloride 7.5 mL - 83 mg

Potassium bicarbonate 5 mL - 100 mg

After further reading I now understand that the TDS meter is not really something I should take as reference after mixing the minerals, so I guess that answers my original question.

Re. Remineralising by mixing tap water: this is not something I tried with the RO water, will it give similar results to mixing minerals?

Thanks!

MediumRoastSteam

erkal - search function can do wonders… sometimes 😉

https://coffeetime.freeflarum.com/d/1481-do-you-distill-your-own-water-i-know-down-the-rabbit-hole-we-go/3

erkal

MediumRoastSteam But I do not have a distiller tho, just an RO.

MWJB

erkal Re. Remineralising by mixing tap water: this is not something I tried with the RO water, will it give similar results to mixing minerals?

Do a postcode search on your water supply, then look at the in-depth report, in particular total hardness as CaCO3 and Alkalinity as CaCO3.

Then work out how much you need to add to your RO DI water to achieve 40-60mg/L alkalinity as CaCO3. You can do this with a jug on scales in about a minute. You are really mainly looking for thse 2 parameters, which most tap water has in spades.

MWJB

erkal Epsom salt 15 mL - 369 mg

Calcium chloride 7.5 mL - 83 mg

Potassium bicarbonate 5 mL - 100 mg

Is there a reason why your bicarbonate (alkalinity) component is so low?

I’d recommend you get a KH/Alkalinity drop kit to test your brew water.

erkal

MWJB No reason. I am just trying out recipes I find in forums, albeit rather blindly as I don’t know much about it all so I try and go by taste. If you have a better one I am happy to use that instead?

I’m not really after experimenting, I just want one that works good and I’ll stick to that.

I can find my water data from the company but do you think this will be as good as adding minerals myself and also will it not scale the machine? My tap water is around 300ppm maybe more…

MWJB

erkal I can find my water data from the company but do you think this will be as good as adding minerals myself and also will it not scale the machine? My tap water is around 300ppm maybe more…

You are already adding hardness, which is the source of scaling, the machinew won’t care if it comes from your concentrate, or from the tap. It just cares how much.

I’d aim 40ppm alkalinity as CaCO3 to start with. Hardness could be 40-80, best to stick to 1.5x the alkalinity if it’s easy to do.

MWJB

erkal No reason. I am just trying out recipes I find in forums, albeit rather blindly as I don’t know much about it all so I try and go by taste.

What if the water that tastes best in uncontrolled comparisons damages your boiler, that would be a lot of effort for nothing.

You added 100mg of potassium bicarbonate to 2.5L of water, this translates as 20mg/L alkalinity….if this is a recommended recipe anywhere (it isn’t as far as SCAA, SCAE, SCA, Shulman, Water for coffee book, Zurich university coffe science dept. are concerned), it probably shouldn’t be (risk of corrosion).

erkal

MWJB

OK I need to swap out the water asap.

So are you saying 3:1 ratio for Hardness:Alkalinity?

Thanks!

MWJB

erkal So are you saying 3:1 ratio for Hardness:Alkalinity?

I am saying aim 40ppm alkalinity, with a hardness of 60ppm +/- 20ppm depending on how easy this is to achieve.

Less of a focus on the ratio, more on the target values.

erkal

MWJB Ok, I added bicarb until TDS read 40ppm and then added magnesium and calcium until it read just above 80ppm. Time to make another cup I suppose :)

Thank you!

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