Well Water Analysis — OK for orchids?

[Orchid Whisperer]

James, I have to disagree on the effectiveness of a typical ice maker filter for removing viruses, etc.

It all depends on the micron size of the filter. There may be some variation in micron size for those refrigerator ice maker filters, but 0.2 micron is typical. Smaller is better for removing contaminants, but 0.2 microns is not effective for viruses or many chemicals. The CDC provides a guide to filtration systems and what they can remove: CDC - A Guide to Drinking Water Treatment Technologies for Household Use - Camping, Hiking, Travel - Drinking Water - Healthy Water The refrigerator filter is nowhere close to functioning as well as an RO unit.

---------- Post added at 06:48 AM ---------- Previous post was at 06:40 AM ----------

I looked up that pure source 2 filter, it is activated carbon based. It will remove contaminants that can be adsorbed onto the surfaces of the carbon particles. I did not see a micron size specification.

[King_of_orchid_growing:)]

I'm not familiar with ice filters, but I do know that when filtering for viruses in water, it's the microns that count. A virus has size. If the filter has holes large enough for the virus to pass through, it will.

[Subrosa]

TDS is a very deceptive thing. A reading in the 500 range when the predominant contributor is limestone is one thing. Try growing with water in the 500 range in which the predominant contributor is sodium chloride. Same reading. Very different results. As far as killing viruses, if it's that important uv is the way to go.

[james mickelso]

The bicarbonate is 579ppm. Very high and very hard. The roots won't like it. As for filters on refridgerators it does indeed depend on the pore size of the filter. Here we buy filters for my friends refridge and it is a three stage filter which takes out particles down to .010 microns. That takes care of most pathogens. UV is fine for disinfecting water that has been processed to a high degree. But any contaminates could shield virus. And again, there is no residual disinfection. 100 ft down the line someone doesn't put in a backflow device on their sprinkler system and their dog takes a healthy crap right on a sprinkler head and there could be the potential for contamination of the waterline by fecal coliform. I'd rather use hypochlorite and keep a small residual in the pipeline all the way to the end where I live. I don't trust my neighbors. I've been in the water field for longer than most of you have been around. I carry California State certifications in both water treatment/distribution and wastewater treatment. Many newer water facilities are going with UV disinfection but the score isn't in yet.

[Orchid Whisperer]

James, it all depends on the micron size of the particular filter CambriaWhat is referring to. Since we don't know that size (yet), I have to assume it is a typical ice maker filtration system, and does not come close to the 0.0001 micron size that is typical for an RO unit.

I'm a water guy too BTW, since 1982. Consultant since 1991.

Ultimately, I think we agree that the real issue with the water is the material dissolved in the water. To fix that problem, either removal by reverse osmosis, or dilution with better water (rain, etc.) will be needed. Since some of CWs plants may be more tolerant to water quality, perhaps dilution with rain water, may be all that is needed?

Correction: Looking back, Hiester mentioned the PureSource II™ filter, not CW.

[orchidsamore]

If you think your water is an issue, my well water is 1700 PPM. Liquid rock I call it.

This level of solids buffers the water into the alkaline region. My PH is often close to 8.

Both conditions are bad for orchids, yet I am a commercial nursery. Most commercial nurseries use injection systems to inject citric acid into the water system at a constant rate. I do not recommend trying to lower the PH manually. It is too easy to make mistakes.

What makes it possible for me is that 6-8 months a year they get tremendous amounts of rain water. PH 7 and no dissolved solids to care about. I grow outside year round.

Everything bad is flushed out of the pots.

Even those with low TDS remember they build up over time as you water. Orchid pots need to be flushed periodically. A couple of times a year is enough if you do not have high TDS.

---------- Post added at 08:31 AM ---------- Previous post was at 08:15 AM ----------

Reverse Osmosis is excellent water for all plants. I know one grower that uses it exclusively. He believes he gets much better growth to justify the expense of RO water for a nursery.

Remember that RO is totally pure so no Calcium or magnesium or other trace elements. You need to add the. Calcium and magnesium are the most important so buy fertilizer labeled Cal Mag which is specifically made for RO water.

[Subrosa]

If viruses are a concern put a uv unit at point of use.

[james mickelso]

Again, the water has to be fairly pure (no dissolved solids at all) for UV to be considered effective. Virus and some bacteria can be shielded from the UV light by those solids. There is no residual with UV or ozone.

[Ray]

As this is intended as a discussion about the applicability of water for orchids, why are we bothering to discuss bacteria and viruses?

[Hiester]

Originally Posted by Ray

As this is intended as a discussion about the applicability of water for orchids, why are we bothering to discuss bacteria and viruses?

Prolly my fault, as I mentioned the 'frig filter, sorry. I was just wondering in my own mind if I should be using the filtered water from the 'frig (left overnight to warm up to room temperature) for watering my plants, or not. From the sounds of it, it won't hurt anything to do so.

I sent my water authority an email inquiry. The response was that there is always a residual chemical disinfectant in our municipal supply, but the minimum can be used under ordinary circumstances due to the ozonization process.