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Post by meadowview on Dec 24, 2009 16:14:17 GMT
Hi Folks:
Can I hear from you on the quality of reverse osmosis units you are using for nepenthes cultivation? I did a search on the Forum but I was surprised to find nothing posted about reverse osmosis.
I'm looking for a unit that can supply 3-5 gallons per hour. Look forward to your comments and Happy Holidays!
Sincerely,
Phil Sheridan Director Meadowview Biological Research Station
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Post by jdallas on Dec 24, 2009 17:00:56 GMT
Hi Phil, You probably don't see much on R.O. units regarding Nepenthes since they are not nearly as sensitive to hard water as many other cp are. Since they don't sit in water like bog species, minerals don't build up as quickly either. We use purified water in our nursery on all our plants, but in a pinch in the summer when demand for North American species is high we will use our regular well water on Nepenthes. We us a GE Merlin R.O. unit to purify water for the rest of the nursery. We have 600 gallons of water storage. Merlin's can put out around 700 gallons a day. After hours of research this is the unit we decided on since it is the most bang for the buck. Merlins cost $350 - 400, and we are getting over a year out of our membranes at very heavy use during the summer. (The unit runs 24/7) The unit is designed to be an "On - Demand" unit for homes, but seems to work very well in a heavy use setting such as ours. When the unit was new the input water was around 130ppm with most of the minerals being calcium and magnesium. Output was around 10ppm. Right now our output is around 25 ppm, but it has to do with the seals on the membranes. ( I didn't use the silicone lubricant correctly when I replaced the membranes; word to the wise to read all the directions. After a couple trips to the hardware store I was able to retrofit it to work on 3/4" garden hose settings, and we use the discharge water on our vegetable garden. Jeff Dallas Sarracenia Northwest
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Post by Hermopolis on Dec 24, 2009 17:17:56 GMT
Hi Phil,
I use a Watts RO unit designed for home use. They make commercial units designed for producing up to 10,000 gallons per day. The throughput of any RO unit is largely dependent upon the membrane, which is the rate determining step. I decided that the 5 gpd membrane was too slow and upgraded the membrane to a 50 gpd; they now make 75 gpd membranes for my unit. Much of the secret to using a RO unit successfully for a large number of plants is to have a large storage tank, so the unit can purify water when you aren't using it.
However, when looking at a RO system be sure it is at least a 3-stage system. These produce cleaner water and make the membranes last longer.
-Hermes.
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Post by meadowview on Dec 24, 2009 17:36:11 GMT
Hi Guys:
This is some very useful information. We refurbished our shallow well (25 feet) last year to produce crystal clear water (long story). We have had a lot of rain lately which has penetrated the aquifer and very slightly disturbed the supporting marine clays. As a result there is an almost imperceptible haze in the water. However, the 2-3 gph humidifier is putting a slight dust on the Nepenthes leaves and I want to head this off before we have a problem.
What type of storage tank do you use? Is it a pressurized in-line tank or at atmospheric pressure with separate pump? Also, what about sanitizing lines. Do you do any chlorination?
Best,
Phil
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Post by Fred P on Dec 25, 2009 1:55:32 GMT
Hey Phil (Merry Christmas from the West Coast), I also use a Watts system. It's a complete set-up for under your kitchen sink for just under $150 (and free shipping). This particular one is a 5 stage 50GPD system (a little over 2G per hour so smaller than what you need but its the same idea). Here is the link for the one I purchased which includes a 2.8 gal storage tank (you can buy larger ones) and the faucet for the kitchen sink. www.affordablewater.us/5-Stag...Yn1S6jmipDalaWI use 15 to 20 gallons per day for my collection and this system has been working great for me for a year and a half now. I have extremely hard water here in southern California...about 550 to 700ppm and this RO System brings it down to 10ppm. I just fill jugs of water and store them in the garage. The tank is pressurized and I've never done any sanitizing of the lines (After I installed it, I just let the unit run for 2 days and kept emptying the tank to clean it out). We also use it in place of buying bottled drinking water. Good Growing, Fred
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Post by jdallas on Dec 25, 2009 16:43:53 GMT
Hi Phil, These are the type of tanks we use. We have started out with one 300 gallon and now we have two. www.tank-depot.com/productdetails.aspx?part=TC3581IW We will probably add a third this summer along with a second Merlin. We pump it out with one of these: www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=47906. The pump has 1" fittings, so spa hosing works great. You do have to attach a foot valve for the hose going into the tank so the pump can keep it's little tank pressurized. The output on the pump we made the same as 3/4" garden hose so we could use it all over the nursery. If the whole set-up can be kept in a shed to keep it above freezing it is good. We don't have that, so I have the pump and Merlin in a Rubbermaid storage box with a small heat source, and heat cables on the 1" line going to the storage tanks. During mild freezing weather you don't need to worry about the tank, but during very cold weather systems I use a horse water trough heater to keep it thawed out. Give me a call if you would like more details. I also show and explain our set-up on our video, Grow Carnivorous Plants Volume #1. Jeff
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Post by Aidan on Dec 25, 2009 19:56:38 GMT
If you can lay your hands on them, recycled 1,000 litre IBC tanks are hard to beat for bulk water storage -
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Post by meadowview on Dec 25, 2009 22:08:56 GMT
Hi Jeff:
I read over the Merlin manual. We are on a shallow well pump with 30-50 psi. The Merlin requires a minimum 40 psi so I'm not sure yet if we would need a booster pump. If you know the answer let me know or I'll call manufacturer.
You mentioned the Merlin is on-demand. How much water can it supply in an hour? Obviously your hourly needs far surpass what it can do but I think it might be able to meet the needs of our humidifier (which has a several gallon sump). We have two spare water tanks of 65 and 250 gallons so we have no problem on reserve tanks if needed.
Best,
Phil
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Post by meadowview on Dec 26, 2009 19:34:15 GMT
Hi Folks:
We checked our well water today and got readings between 150-260 ppm. This water is only being used in our greenhouse humidifier, not to directly water the plants. We use pond water to water the plants and this has always been very acceptable.
So.. the question becomes whether this relatively high tds in aerosols is really a problem The greenhouse turns into a cloud when the humidifier comes on and there is clearly deposition on Nepenthes leaves. Obviously, it isn't going to hurt us installing an RO unit on the water supply side to the humidifier. Interested to hear your comments.
Best,
Phil
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Post by rsivertsen on Dec 26, 2009 20:55:09 GMT
Hi Folks: We use pond water to water the plants and this has always been very acceptable. Hey Phil, Longwood Gardens tried that a few years ago and wound up getting hit with a terrible nematode infestation that wiped out about half of their most prized plants, including all their Hawaiian Silver Sword plants. Be careful! - Rich
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Post by meadowview on Dec 27, 2009 16:00:40 GMT
Hi Rich:
Pathogens are definitely a consideration with pond water. We have a 50 micron filter on the system but that of course still lets a lot through. My main concern with pond water is that we run a misting system on the Nepenthes with pond water. When this system comes on we vacate the greenhouse to avoid inhaling the mist and possible lung infection.
A much better solution to multiple issues in the greenhouse would be to use an RO system, with our in house UV water sanitation and 0.35 micron filter, to feed both humidifier and misting systems. It looks like the Merlin RO system could easily do this.
Best,
Phil
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Post by rsivertsen on Dec 27, 2009 22:44:10 GMT
Pathogens are definitely a consideration with pond water. We have a 50 micron filter on the system but that of course still lets a lot through. My main concern with pond water is that we run a misting system on the Nepenthes with pond water. When this system comes on we vacate the greenhouse to avoid inhaling the mist and possible lung infection. That can be very dangerous to release pond microbes into the very air that you breathe. Perhaps an inline UV filter might reduce this risk, they're available at almost any water purification outlet and some backyard pond shops plus a few large home and garden centers. - Rich
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Post by meadowview on Jan 4, 2010 22:58:13 GMT
Hi Jeff:
Do you have a vendor that sells the GE Merlin system that actually has a phone and returns phone calls? I would like to get this system but want to talk to a real person first, something you don't always get anymore. I've called one company several times but no return call.
Best,
Phil
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zhilin
Full Member
touch the sky, reach the star
Posts: 294
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Post by zhilin on Jan 12, 2010 0:41:20 GMT
Hi, I am interested in this machine. But I don't need much water everyday because I have only small number of cps. Generally, One Gallon is enough for my cps for One Week. So I would like to buy a small RO Units. Can anyone give me suggestions, especially the product website? Thank you very much!
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Post by Aidan on Jan 12, 2010 15:03:54 GMT
You would be better off seeking an alternative solution. The volume of water that you require is currently too small to justify the outlay and running costs of a RO system. They are designed to produce 10s to 1,000s of gallons per day.
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