New to Reverse Osmosis

[DavidCampen]

Originally Posted by Pilot

I'm on a well as well and I have a total dissolve solids meter that measures ppm before my DI chamber and after. My before reading shows 1-2ppm and my DI reads 0ppm. So either my well water is quite good or my system is doing an exceptional job (or both).

From what I understand you to be saying, you have a combined RO/DI system and you are measuring a TDS of 1-2 ppm in the RO water before it goes into the DI system but you don't say what the TDS is of your well water that is the feed to the RO system.

Combined RO/DI systems are commonly used by aquarium hobbyists but standard household RO systems do not have the additional DI stages.

My self designed and built RO system is producing a product with a TDS of about 10 ppm with a feed TDS of 200 ppm but I am using a very low reject to product ratio of only about 1.2:1. If I used the higher reject to product ratios of 3:1 to 6:1 that are common with commercial home RO systems I would expect to get a product TDS closer to 1 or 2 ppm.

In regard to precipitates, I wonder if something I have attached to my RO/DI unit might help you. I have a bi-pass valve that when opened up, sweeps the membrane quickly with water and removes precip build up. My unit is fairly new (only a week old and I use it only for preparing water for my marine aquarium) but fellow hobbiests in the marine keeping forums say this "flush valve" really helps prolong the life of their membrane and filters of those who have hard water.

Yes, but the OP does not appear to have a problem with precipitates clogging his RO membranes. Prcipitates clogging the RO membrane would manifest as a reduction of throughput which is not what the OP is reporting.

[orchidlover69]

Well, the tds meter is here! Between the softener and the RO unit, tds clocks in at 542ppm. After the RO I am showing 45-48ppm depending on which glass I use to test the water. What should I reasonably expect to aim for with RO water? I see online ideal drinking water for RO is 0-50ppm. Does that mean, I am within spec for orchids?

[Eyebabe]

Originally Posted by orchidlover69

I see online ideal drinking water for RO is 0-50ppm. Does that mean, I am within spec for orchids?

I am fairly illiterate about RO and am just beginning to use it myself.
However, your one comment above I found concerning from my research.
RO water is acidic and should have a pH around 5. You cannot drink water that is this acidic without long term health issues arising. If your system is designed to give you "drinking quality" water then it cannot be a true RO.

[DavidCampen]

Originally Posted by Eyebabe

I am fairly illiterate about RO and am just beginning to use it myself.
However, your one comment above I found concerning from my research.
RO water is acidic and should have a pH around 5. You cannot drink water that is this acidic without long term health issues arising. If your system is designed to give you "drinking quality" water then it cannot be a true RO.

I have a "true RO" system. I know this because I designed and built it myself. I drink the water from this system all the time - actually I use it for making tea, of which I drink a lot.

Absolutely pure water would have a pH of 7.0 but deionized and RO purified water will have a slightly acidic pH because of dissolved carbon dioxide from the atmosphere. It can still be consumed without harmfull effect.

[DavidCampen]

Originally Posted by orchidlover69

Well, the tds meter is here! Between the softener and the RO unit, tds clocks in at 542ppm.

Wow, you do have really hard water. It is probably best for your RO system, to reduce fouling of the RO membranes, that you feed it softened water as you do.

After the RO I am showing 45-48ppm depending on which glass I use to test the water. What should I reasonably expect to aim for with RO water?

I would guess that that is OK but I am a neophyte orchid grower so I am hoping that someone more knowledgeable will comment.

The RO water that my system is producing has a TDS of 10 ppm (produced from a feed water with a TDS of 200 ppm).

I mix this 10 ppm TDS RO water with Dyna-Gro Orchid Pro liquid fertilizer at 1 part to 1500 to get a fertilizer solution with a TDS of about 200 ppm. So I think that even with your 50 ppm TDS RO water you should be OK.

[Ray]

I suspect that the problem is that the softener is not properly tuned, so is adding an excess of NaCl to the water.

If it is adjusted properly, you'll probably get a lower TDS from the RO.

As to the drinking part, I have an RO system that feeds my refrigerator for ice and drinking water, but I added a mineralizer cartridge to the output so that Ca and Mg are put back in, and it tastes better too.

[Eyebabe]

Originally Posted by DavidCampen

I have a "true RO" system. I know this because I designed and built it myself. I drink the water from this system all the time - actually I use it for making tea, of which I drink a lot.

Absolutely pure water would have a pH of 7.0 but deionized and RO purified water will have a slightly acidic pH because of dissolved carbon dioxide from the atmosphere. It can still be consumed without harmfull effect.

sorry to be off topic here a bit

http://www.who.int/water_sanitation_...ineralized.pdf

...you should not drink it then imho