I am also interested in collecting rain water for better water quality. I am considering rain water as a green alternative to RO. I would like to know what others think related to the overall water quality issue and how to achieve the best quality.

I think you would have to be a botanist/scientist to understand this business. I happily and most people in our orchid society use the local tap water without even thinking about the TDS. Just looked up the report from the supplier and it is about 120 TDS.
The question arises TDS of what and are all the bits that make up the TDS harmful to orchids.
I do have a 3000 litre rain water tank with its label. "Unfit for human Consumption". It was obtained during the last prolonged drought when there were restrictions on the times that you could use a hose. The only problem with the tank water is that you have to use an orchid fertiliser with trace elements every so often.
You might be able to find past posts on TDS by using the search facility.

If you switch to RO and also the appropriate fertilizer, I think you'll notice improvement in many of your plants. Cymbidiums, Au Dendrobiums and many Catt hybrids probably don't care but everything else will look better. Your choice is really between DI and RO.

DI is more expensive in the long run but effortless on your part. A unit is usually rented and maintained and recharged by the rental company. No upfront cost but the ongoing cost of recharging it as you use the water which comes to you at city water pressure.

RO is more expensive to buy and requires some Rube Goldberg plumbing skills as the water dribbles out and has to be re-pressurized. After the initial cost it is much cheaper to run and in the long run will save you money. Check out 'Back to Nature Filtration', I have used their system for over 10 years and have been happy with their equipment and customer service.

If your only sensitive plants are a couple of Masdies, use the usual fertilizer. If you have a bunch of sensitive plants switch to MSU RO fertilizer which is more expensive but specifically modified for RO water.

Nick

I have used an RO undersink unit for many years. I started out with a Culligan unit but now use a cheaper unit from Lowes. Simple hookup (my daughter hooked it up)and it provides about 3 gallons every 3 hours. I also have rain barrels.

When we lived in NY we had well water and it was terrible. When I put in the RO I saw a huge difference in my plants. I couldn't grow certain orchids at all with the tap water. RO made a big difference.

Now in Florida, I would not use the tap here for drinking or watering. Before we moved in, I went to Lowes and bought their unit for under the sink. It comes with its own faucet which goes in the hole for the soap dispenser.

I use it exclusively for drinking, cooking, etc. You can hook it to your ice machine if you want.

I use MSU for RO/rain. I also use various other fertilizers without a problem. Sometimes I'll add about 10% tap as a buffer for the RO.

I feel it pays for itself quickly. The water tastes delicious also.

Jane

Thank you for your replies. I have a couple of masdies and phrags that I am worried about the most. A few of my other orchids (a couple of dendrobiums and oncidium) are having some leaf tip die back but it is very minor. I have switched to distilled water for now but I want something more sustainable. So I will look into the RO systems that you have mentioned. How portable are the systems once they are installed? I am considering moving at the end of the year.

I also I can get the MSU RO fertilizer in a couple of weeks. I appreciate the advice.

Both units are portable. When we sold our house in NY, we took the Culligan with us and installed it in the rented townhouse we lived in for 2 yrs. Simple removal, install.

We left the Culligan behind at the townhouse because the owner loved it and bought it from us.

When we moved to Florida, we heard Lowes offered a good unit and we bought it. Same as the Culligan, holds about 3 gallons. Easy install and the replacement filters are easy to buy yourself. Culligan was more expensive and you are forced to buy their filters.

Both units require filter changes about 6-8 months and the main filter about once a year. Mine lasted almost 2 years. Depends on the amount of use and the amount of sediment in the water.

Jane

For a short term fix, the super/final rinse cycle at your local hand wash carwash probably uses RO water?

For $1.75 I can get about 7 gallons (I re-use old 2.5 gallon DI water jugs and can fill @3).

Good luck,

Bob

There you go!

Jane

This is great information! I have just been purchasing distilled water by the gallon for the short term. But it is not the most financially sound option for any sustained period of time. While I figure out which ro system to go with I will check out the car wash water. :)

This is great information! I have just been purchasing distilled water by the gallon for the short term. But it is not the most financially sound option for any sustained period of time. While I figure out which ro system to go with I will check out the car wash water. :)

I've actually tested reverse osmosis water versus a water softener for doing a final rinse for a car and I must say that the reverse osmosis water worked best. Problem is you have to be careful with the brakes because they are metal. So the best thing to do if you plan to use reverse osmosis water is to use a phosphate filter to protect the metal from corrosion.

It's also good to drink =). You can actually just get any kind of RO system and post filter treat it and just buy a large storage tank.

Here is a link that might be useful: Reverse Osmosis Systems