I continue to experiment with ways to get water to my Synchronika. I used the Barista Hustle SCA recipe water and that made good coffee but had a slightly brackish taste on its own and was not great for tea. Went to RO plus a remineralizer cartridge (RO/RM) and that seemed a bit too soft (no real data here, just a feeling). However, adding 10% Evian yielded water that tasted "right". It made good coffee, good tea, and tasted sweet and pure on its own.

Specifications of my water as CaCO3 equivalents: The RO/RM is about 25 mg/l (mostly from Mg+2) and 10% Evian adds about 30 mg/l (mostly from Ca+2), so I am running about 55 mg/l total hardness, with a mix of calcium and magnesium hardness and some bicarbs and other compounds from the mineral water. That is a bit softer than SCA water (about 80 mg/l). I have no idea which water (mine or SCA) makes better coffee in my machine, but I do know that my water tasted better on its own and in my wife's tea.

So I have water that I am happy with, but now I want to get the preinfusion function working on the Synchronika. That requires line pressure on the water inlet. Got a Flojet pump and one of those big blue BPA-free plastic bottles from a water store. Cleaned everything thoroughly and started to make coffee. By the way, be careful buying remineralized RO water from a water store. I tried but it tested very strangely with my Hatch water test kit. The indicator changed color as soon as it was added to the RO/RM water - before even adding any titration reagent.

Back to the Flojet. I'm not going to discuss the coffee made with line pressure water, because I have just started playing with preinfusion and there are too many uncontrolled variables running about. However, the Flojet is now disconnected because of one observation in which I have high confidence. It corrupts the water. My wife first noticed that her tea tasted "funny". Then we did repeated blind testing, comparing water from the Flojet to water from the big blue bottle that fed it. Aaargh. The pump adds a strong artificial taste, a bit like plastic, a bit like burning insulation. Undrinkable.

I could add a polishing filter to the output of the pump but, hey, why would I go to all this trouble to create great water and then corrupt it. The real answer is to understand the Flojet. Is my pump defective or is this something they all do? Does it just need to run a few more gallons of water through, or is this a forever thing? I am leaning towards forever, as there is no improvement as I run more water through the pump. Also, I have seen other reports of taste problems with Flojet systems. Until I have this better understood, the Flojet's gone. Caveat emptor.

One solution would be to put a finishing charcoal filter as the last thing between your water supply and the machine. If you added an accumulator it would be after the accumulator. That should help take care of off tastes from the bottle, pump, water lines, and accumulator. It should also handle small amounts of residual chlorine that might be there after using bleach to sanitize the system and failing to perfectly rinse.

cunim wrote:By the way, be careful buying remineralized RO water from a water store. I tried but it tested very strangely with my Hatch water test kit. The indicator changed color as soon as it was added to the RO/RM water - before even adding any titration reagent. I suppose that means the water store really remineralized that RO water. Lord knows what was in it.

Hach 5B kit? If so, when it goes straight to blue (rather than pink) after adding the first (indicator) reagent, that's an indication of little or no hardness minerals (divalent cations such as calcium or magnesium) in the sample.

I had to add a filter after my flojet/accumulator setup also. I was getting a rubber taste from the bladder in the accumulator even after tons of flushes.

Any way to mount the water bottle high and use gravity feed?

No filter. Does it really make sense to create a pure and fine tasting brewing water using RO filtration mixed with mineral water (pond fairies and water nymphs sing as it pours), and then pass it through a pump that puts scuzz into it? Yes, you can clean the scuzz out (or at least the taste part), but there is something wrong with this picture.

To be fair to Flojet, I don't think this 5000 series pump was designed for taste-critical applications. More suitable for RVs that need showers and dish sinks. Flojet's tech support department says that they have had complaints of this type of taste. Wouldn't tell me how many but some. It is a known issue and they don't know if it is the tubing or the pump itself. They do know that, once the taste appears, it does not go away. Their view seemed to be that they sell thousands of these pumps a month so they must be good - right? Flojet does stand behind the product and I was told to exchange it. I am not sure if I will do that, or just return it. I would hate to go through this whole hassle again with a replacement pump that may well do the same thing.

Yes, the Hach 5b. As you can tell, I am not much of a chemist and am learning as I go. To clarify, the Hach powder goes blue as soon as I add it to the store-bought remineralized water. In contrast, the dissolved powder turns my home made Kinetico RO/RM water pink until about two drops of 50% diluted reagent are added, indicating 1.5 grain/gal. As you point out, the instant blue is what pure RO water does. So - the water store is selling remineralized RO water with almost no mineral in it.

As to hanging a 5 gal container from the kitchen ceiling, I would be unlikely to survive an attempt to do that (wife). Good idea though. I am sure there are better pumps out there and one of those is probably the best solution. The other alternative is just to add a second RM cartridge to the Kinetico system and end up with about 50 mg/l, mainly from Mg+2. The reason I am looking into pumps is that I can always adjust the water dispensed with one of the those. The Kinetico water is what it is.

I've been very satisfied with the performance of Aquatec pumps in the water delivery system for my espresso setup. No detectable off-putting tastes.