Although the prices seem reasonable using an RO filter to clean up 'filthy' water is unadvised. At household water pressures ~45psi RO filters waste four gallons of water for every gallon that they produce. A carbon block filter designed to remove particulates and other chemical and bacterial impurities is a much better purchase. Maybe even a Brita or Pur unit would work for you.

H

I have been using RO for 8 years now and it works great. The waste water can be converted back into your line or you can use the waste water to water other plants. Its no big deal, your orchids will reward you with new growth and pretty roots.

I agree about the waste of water to produce RO at home. Our tap water is unfit for orchids, except for leaching, and I buy RO water by the gallon at a local grocery store.

My info on the carbon block filter is zilch but something to look into for myself. Thanks, Howard.

Another option might be collecting rainwater, depending on your living situation.

Whitecat8

I had a RO system installed under my sink. The tank holds 3 gallons. I have well water which the plants do not like. It doesn't taste good either. But we have no choice as the town never put in water lines. I had Culligan install it. The filter lasts approx. 8 months and is supposed to be fine enough to remove bacteria also.
I have seen a tremendous change in my orchids and other indoor tropical plants. No more brown tips, much healthier growth. I haven't run into pH problems, which I did before.
I felt it was worthwhile investment.

Jane

But I also have a number of large rain barrels which I use whenever they thaw out.

I still believe that the original poster is best served by a water filter designed to remove particulates rather than the very specialized function of the RO membrane which is designed to remove dissolved minerals or other chemicals. Using an RO filter on water that isn't hard i.e. with a TDS over 300ppm just doesn't make sense to me. A $16.00 Brita filter can do the same task. Perhaps some determination of just what the o.p. meant by 'filthy' should be undertaken to really clear things up (get it).

H

Hi
I debated a long time on whether to get one of these systems of not and decied to go with a rainwater collection system..There is not only the first cost but the upkeep on RO systems. Couldn't really justify the expense and upkeep for the whole house especially since I can buy it for 20 cents a gallon lol My main use for an RO system would be for the fish tanks and rainwater is great for this purpose.
Rainwater goes into the fish tanks and tank water goes to the plants. This should create a semi- hydroponic system.
Main problem has been that 80 gallons is not enough water . Another is that during heavy rains the purge system for the large fish tank is exchanging at least 300 percent lol. That from only a four inch rain.!!
Anyway if you decide to go with a Ro system be sure that the capaciity is large enough for your needs and be sure to check on the cost of replacement parts.
gary

I wish I could collect rain water, but it just doesn't rain that much here. I started thinking about water quality when I could see INSTANT growth spurts after I put my orchids outside in the rain(in the rare instances it does rain here). I already have a aquasana filter system under the sink but is not RO and I still see salt deposits on the leaves and potting medium. My tap water was once measured (according to my city's reports) at 500 TDS.

But to the poster that lives in NYC, are you saying that the RO is a waste of water or that the Brita should filter everything out that matters.

All I know is that I saw significant changes watering with rainwater rather than filtered water, and the RO system, i am guessing, is as close to rain water as you can get.

To answer your question, yes different RO systems filter better than others. This is usually reflected in the price and in the number of filters that the system has. But for orchids its not really important to get the best system you can get. A system delivering water at 30 ppm (parts per million) should be fine. The more expensive ones will purify the water even further but that's not critical for our purposes here.

Carbon filters like your aquasana system remove chlorine heavy metals and inorganics, but they do not remove salts. That is why you still get salt deposits on your plants.

How many plants do you need to water?
I believe the Watts system at Costco is an undercounter type with a small 2 or 3 gallon tank. If you have a small amount of plants I would suggest buying water from the vending machines at supermarkets. In my neighborhood it costs $1 for 5 gallons which you'd have to make 750 gallons of RO water to break even. Even then, that is not including the additional costs of new filters and the wasted water. If you have many plants or plan to have many plants a larger RO system would be more useful. The RO system I have right now is a portable system that I connect to my garden hose. The system dumps RO water into a tank and dumps waste water into another tank which at a later date I add hard water to and use for watering outdoor plants. I use a submersible water pump to pump out the RO water from the storage tank.

I purchased my RO system for about the same price as the watts at costco. My line water comes out at 300 ppm and after the RO system comes out at 30 ppm.

If you do decide to buy an RO system, you will want to get a pH meter. RO water will be acidic when it comes out and after adding fertilizer the pH will drop even further. So you will need to add hard water back in to bring the pH back up or add pH modifiers.

Personally, I think the whole process is a pain to do and rarely do it because generating 30 gallons of water takes about 6-7 hours with my system and I can run through that 30 gallons in a day or two during the summer.
Right now, all I run is a carbon filter in-line with my garden hose. All I care about right now is in removing chlorine from the water, but the ppm remains the same. One day I may go back to RO if I get a faster system with an auto shut-off that I can leave permanently connected to the water line.

Hope that helps in some way.

A carbon block filter will make your water taste and smell better, but it will not help your TDS problem. My water has a similar TDS, and my RO system gets it down to 12-15. I bought a system from Airwaterice.com for $200 several years ago. It has 3 filters (10,5, and 1 micron) in front of the RO membrane. The line coming out from the membrane is split. One line goes to a 35 gallon rubbermaid garbage can which I use to store water for the orchids. The other line goes to a carbon block filter and then to a 2 gallon pressurize tank which we use for drinking water. The garbage can has a float valve (also available from above web site) which cuts off the water when it is full. The RO system has an automatic shut off valve as well. Ongoing costs are approx $20 each year to replace all the filters. The RO membrane should be good for several years as long as you replace the filters regularly. Mine is almost 3 years old and still delivering good performance (as measured by TDS). Replacement RO membranes cost $39.

RO water is not really acidic, it is very near pH 7, but since it has no salts there is no buffering capacity and adding fertilizer drops the pH precipitously. I use MSU formula for RO water and add Pro-Tekt to raise the pH to near 7.
The question is, how much water do you need each week? I use approx 70 gallons per week so it is well worth it.

Well,been there, I bought a system which does work but was not cheap, supposedly 1000 gal per day, it has 3 filters including one which is a membrane filter. This led to other things, such as the tank it fills, with the float switch in it to automatically turn it on and off. Then you need a pump so you have water pressure. You can't just run the hose directly from the filter system. I did get most of this on ebay and my brothers did the plumbing, but everything added up, the plants do a lot better with it also.

A RO system can be more expensive than the water from the store. I bought a system for the convience more the price. I was tried of lugging five gallons jugs back and forth every week. I also bought a system that has 1 year filters and a three year membrane. These costs really do add up. 100 bucks per year or 25 per year and 50 every third year with my system.

Here is a link that might be useful: My Review on Reverse Osmosis

Sounds like an RO system is the way to go for the OP.....

On a tangent... for those of you curious about the effect of a brita filter:

Straight from the tap: 285ppm 7.8 ph.
Thru a brita filter: 180ppm and 6.4 ph.

I don't have the option of an RO system or rain, and will not lug 10+ gallons of distilled home a week (esp as I can't find a convenient seller that will let me refill bottles), so many of mine make do with this. I still buy distilled for some of the orchids and cps.

(I figured I should stop lurking on the tenor thread and actually post something about orchid growing.)

Why don't you have the option of an RO system? Dontcha have a sink? I love mine. It sits on the counter and attaches easily to the faucet. When i'm done making water I disconnect it and put it away in the cabinet.
-MB

beeep. No counter space. And does yours fit a 1940s faucet? :P

Anyway, I did some research some time ago and didn't find a system that would work in this rental unit.

Hopefully I'll move soon to a heated gh with a house attached, and I'll be able to treat my plants right ;-)

Well, I can always hope. RE prices have not really gone down around where I am :-(

I posted back in Feb regarding my RO. We have well water and use a water softener. Can't use the tap water on my plants. In summer the plants go out and get watered by rain and the hose (which bypasses the softener). The RO is under the sink, 3 Gals. Until the hose freezes, I keep the garden hose near the door and use that water with the RO or rain-water, half & half. In winter, it is straight RO water with MSU for pure water, which includes buffers and missing minerals. My rain barrel freezes and can't be used.

I like the convenience of the RO water, plus the taste. My set-up was more expensive because I used Culligan an had them install it. It is attached to the water line under the sink and has its own faucet on the sink. You need to have an extra hole in the sink to put the faucet in. I just took out our sprayer and put the RO one in.

An RO system can be attached to an outdoor tap and there are units that can put out 90 gallons a day. All you need is a rain water barrel to collect the water in.
Also the unit I have from SpectraPure in Arizona only costs around $30 a year to replace the two different filters. The membrane will cost in the $100+ range whenever it may need replacing. The turnaround time on ordering is excellent at around 24 hours and they are on the net. I recommend them and receive nothing from them in so doing so this is not spam just my experience.
So large growers even install pumps in their collection tanks (barrels) to pump out the water in order to water their plants but I just fill up jugs from the tap in the barrel to water by hand. There is a great site in Texas that sells a great barrel. Will look it up if interested.

t-man I would be interested in the barrel if you could post the info.

Thanks - Brooke

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Not all ROs are the same. Although the same basic technology is similar, certain features and associated benefits can vary widely. The secret of a high quality RO unit is its ability to produce higher quality of water for longer periods of time. Cheaper RO can produce good water initially but may fail in relatively shot time.

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I doubt that your tank holds three gallons, or even two gallons. Just empty it into a few empty milk jugs and see for yourself. You amy not be considring that the baldder can occupy 50% or more of the volume of the tank. If you are getting three gallons, then you may have an 8-gallone tank.

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Whew! Comparing an RO to a Brita is a pretty wide and overly general comparison. No Pur or Brita filter can come anywhere near the water qualty of even a junky RO. Now it may be true that an RO can be considerd overkill for many applications but one should not infer that they produce the same water.

Andy Christensen, CWS-II