Doodlebug Pump -- FAQ

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Reverse Osmosis

General Questions about Reverse Osmosis Filter Systems

1. General Questions on Reverse Osmosis filter systems
   

Reverse Osmosis

1. General Questions on Reverse Osmosis filter systems

   How does Reverse Osmosis work?

   Reverse Osmosis is a process in which water is forced by pressure (at least 35psi) through a semi-permeable membrane. The good water passes ("squeezes") through a special membrane while the dissolved and particulate materials are sent down the drain.

   Does Reverse Osmosis use a lot of water?

   Basically, the answer is yes. All brands, some more than others. On our basic system, for every gallon of filtered water, approximately 4-10 gallons of water goes down the drain (how much depend depends on your water conditions).

   What does Reverse Osmosis remove from the water?

   A Reverse Osmosis system typically removes dissolved solids such as salts and minerals (lead/mercury for example) out of the water (up to 2000 parts per million).

   What doesn't Reverse Osmosis remove?

   Most Reverse Osmosis units will not take nitrates out at sufficient levels to meed EPA recommendations. Reverse Osmosis will not remove chemicals or bacteria. The Reverse Osmosis membrane itself will not remove chlorine. Our units have a activated carbon pre-filter which will. Many types of bacteria have to be killed before going into any Reverse Osmosis unit. Some bacteria have the ability to grow through the RO membrane. Once on the other side of the membrane, the bacteria can start new colonies.

   Also, if your water has a bad taste to it you probably need an Activated Carbon Filter. The effectiveness of any activated carbon filter is related to contact time. Put another way, the slower water passes through a carbon filter the more effective it will be. For chemical removial, the amount of activated carbon needs to be substantial. For a whole house application this might mean a 2 cubic foot tank unit which is rated for 8-10 gallons per minute. If we only want to remove chlorine and taste, a 10 gallon per minute cartridge filter would surfice. If we are only talking about 1 gallon a minute, a relatively small activated carbon unit can be expected to remove harmful chemicals and metals. It really depends on your specific need and expectations.

   I have excessive nitrates in my water. What do you recommend?

   We suggest a distiller (we do not sell distillers).

   What type of faucets do the above RO come with? With the Aqua Pure AP-R5500 or Purewater PW-RO1 and PWRO2, we supply a built-in air gap faucet. Lower priced faucets are available, but we prefer to only sell RO faucets with built in air gaps. The air gap is built in (underneath) this faucet for prevention of contamination of the waste touching drinking water.
   When shopping for reverse osmosis systems, be sure to check what type of faucet dispenser is included.

   I have an RO system and there is water coming out from underneath the water dispenser faucet. What is wrong?

   More than likely, you have an air gap style faucet. This is a safety feature. If there is any kind of clog or kink in the RO drain line, water will come out from under this style of faucet.

   What is the difference between the TFC and TFM membranes?

   Basically they are the same membranes.

   What if my hardness is greater than 10 grains per gallon?

   If your water is harder than 10 grains per gallon, then it will tend to foul the RO filter prematurely and this will void any warranty. This is the case with almost all brands of RO systems. If your water were that hard we would recommend a water softener.

   Do you carry parts for RO systems?

   Yes, we stock or have available replacement parts for the brands that we sell.

   My pH is 6.0, my hardness is 35 grains, etc ... Can you tell me what I need?

   We can provide you with a free water sample kit; you pay for the shipping only. Just follow the directions and send in your water sample. It will be analyzed free of charge by Aqua Pure. We will provide you with our best recommendations as to what type of treatment equipment you might need.

   In the above example, it appears the water is very hard and will need a water softener. A PH of 6.0 is acidic and may need to be neutralized. A lot depends on a total water sample analysis.

   I've seen RO that cost less than the ones you offer?

   Yes, we could offer lower priced RO as well. We would like to keep you as a satisfied repeat customer, not a "one shot" dissatisfied one!

   If you have spent any length of time looking at our filter and water related catalog items, we know you have seen how low our prices are.

   We do offer various price ranges. This is dependent on value added features the customer is willing to pay for. An example would be: quick-change replacement filters versus replaceable cartridge housings. These product variations do not lesson the overall quality of the units, but can effect price.

   When deciding what Reverse Osmosis units to offer, we elected to sell only products manufactured by Cuno. Above all else, they make a quality line of products.

   We sell their residential product line under two brand names: Aqua Pure and Purewater. Each of these brands are targeted at a specific aspect of the market.

   In our judgement, the lowest priced models in the market place aren't necessarily a bargain in the long run.

   Reverse osmosis systems need new membranes and filters on a regular basis. Make sure to compare those prices and ratings as well.

   Customer satisfaction is very important to us. We think you will agree that buying a "bargin priced" unit isn't necessarily a bargain in the long run.

   The old addage: "you get what you pay for" is particularly applicable to water treatment products.

   Will an RO produce 'pure' water"?

   Many use the word "pure" and many books have been written on the subject. Purified water is a term that has little meaning unless additional qualifiers are added. Such as: salt free, bacteria free, etc.
   Distilled water is probably as close to "pure" as water can get. It is made by evaporation and removal of all solid particles plus dissolved materials.
   Purified water by the reverse osmosis method means that the original water has reduced mineral content. Purified water by ultraviolet light means that the water source was passed through an ultraviolet system, which when properly sized and pre-filtered is capable of disinfecting the water.

   It is generally recognized that no single water treatment method is a catch all for all possible contaminants. Each water treatment method has its strengths and weaknesses and all are dependent on the condition of the water source.

   I've heard that I shouldn't use copper pipes with any/all brand/s of Reverse Osmosis system/s?

   Most brands of RO system will reduce at least 85-90% of salts in water, so you can assume the salt concentration will be about 1/9th of the content in the feed water. Water is a natural solvent. The more pure the water, the more its ability to absorb things it comes in contact with. Put another way,the aggressiveness of this purified water towards the materials into which it comes in contact is a function of its purity. The better the purity, the more its aggressiveness. Piping after an RO unit should therefore always be non-metallic. Don't use copper piping after any (brand of) RO system.

   My RO continues to run. What is wrong?

   Check the storage tank; it might not have enough air in it. The tank should have between 5-10 lbs of air in it when empty. Too much air, however, will cause an RO to shut off prematurely.

   We have been considering buying a large 'whole house' RO system. Would the largest RO units that you offer work for our main water line?

   Yes, but this gets into the area of an engineered product and is not suitable for “On Line” sales. We would be happy to quote you on just about any size unit (including commercial applications). Please contact us with your specific requirements and we will give you a complete price with all of the components you need.

   What kind of warranties do the reverse osmosis systems have?

   All our units have at least a one-year warranty on the components. The manufacturer will replace any defect arising in any of the parts within one year from the date of purchase. Labor for installation is not covered and there is no liability assumed by any of the companies for damage due to water leakage. This is the "standard" in the industry.

   I just installed a new filter cartridge and my water is cloudy/white?

   After you install a new filter (this is the case with any/all brands of filter cartridges) you should run it for a few minutes. Generally cloudy or white water indicates air in the line. This is natural and normal with the replacement of a cartridge. Air will enter in the housing, lines and cartridge. Just run the water for a few minutes and the cloudy conditions will go away (unless you have very cold water in which case it is the oxygen in the water that could be making the water look cloudy). It is always a good idea to run the water free flowing for a few minutes after installing any brand or type of new filter cartridge.

   Is it true that Reverse Osmosis units waste a lot of water? Al brands of Reverse Osmosis units "waste" some water. With some systems it takes as much as 10 gallons of water to produce one gallon. Our systems are much better than that, but please understand, no matter what brand, there will be a significant amount of "waste" water.

   To a certain extent this "waste water" can be minimized in larger size systems, by raising the water pressure supplied to the membrane. It is possible to reduce the “waste water” in a high-pressure unit to 50%.

   I have hazardous or non-potable water. Will an Reverse Osmosis unit give me "pure" water?

   Reverse Osmosis filtering units will not produce sterile (potable) water.
   Some microbial growth is common after water is treated by Reverse Osmosis. If you feel your feed water has microbiological water problems an Ultra Violet sterilization unit of sufficient capacity system might be indicated. Please contact us if you have concerns about this and we will be glad to give you our recommendations.

   Ok, I installed my Reverse Osmosis unit and have my faucet open, but I'm not getting much water. I hear water running down my waste pipe but I'm not getting much water. What is wrong?

   Nothing is probably wrong (assuming you purchased your RO unit from us). The reason for the storage tank in residential Reverse Osmosis systems is it takes a long time to produce RO water. The faucet needs to be in the off position. Then, the tank will (very slowly) fill. On the 30-gallon models it takes at least a day to produce up to 30 gallons. That is only slightly more than one gallon per hour.
   Close your faucet and wait at least an hour and then the tank will be partially full and you can then start to use water. A 30-gallon per day model does not mean that you can use 30 gallons all at once but rather, it can (if all was "ideal") produce up to 30 gallons during an entire 24-hour period. Depending on your water pressure, a 30-gallon per day unit could be de-rated by 50%. Please remember, quite a bit of water is wasted by all brands of RO to produce RO water and that is why you are hearing the wastewater running.

   My RO is almost new and is rated to 'produce' 24 gallons per day but it only produces about 6 gallons per day if I'm lucky?

   Capacity ratings by manufacturers are based on "ideal" situations. Please note, for example, both the pressure inlet and the temperature of the source water affect the production a lot (as well as the quality of the source water as well as the back pressure from the RO bladder tank, etc.). The lower the pressure inlet, and/or the lower the inlet temperature, and/or the worse the quality of the source water = the less the amount of water that is produced by your RO system.

   A "typical" 24-gallon per day rated RO could take over 12 hours to fill the 2-gallon storage bladder tank. This may sound like double talk, but it’s an industry standard rating system. It may not seem to make sense that a 24 gpd rated RO (just an example, it could be a 30 gpd RO) that it takes as much as 12-16 hours to fill a two-gallon bladder tank. You need to be aware of the reality of the situation. It is extremely rare that any brand of RO will deliver near its rated gallonage.

   If your family needs more than 5 gpd and only has a 45 psi inlet you might consider buying a larger than 30 gpd rated RO. If you only have 40 psi we strongly recommend purchasing your RO with a booster pump. This statement applies not only to the RO that we sell but also to the design of all brands of residential Reverse Osmosis units. Most families don't use over 2-5 gallons of RO drinking water and, most families are perfectly happy with a 30-gpd RO system. If your family and/or your water source isn't "typical" then we suggest getting a bigger than 15-30 gpd rated system. Realize that if you have at least 50-psi inlet, fairly clear, 77°F and have the produced water dribbling into a container then the system will probably deliver slightly more than the ratings. Since this is probably not the case, we want to let you know this before you buy an RO system. Inlet water is "squeezed" through the RO membrane. That is how the principle of any brand RO works.

   I bought an RO someplace else and the company went out of business. Can you help me?

   With many products we can help, but, unless it is manufactured by Aqua Pure or Purewater (both of these productes are manufactured by Cuno) we can't.

   Will the above Reverse Osmosis systems that you offer pass my local new construction inspection?

   Since we ship throughout the entire U.S., and every state or local community may have differing requirements, we cannot be sure that your local agency will pass any of our Reverse Osmosis units. We suggest, if "passing their inspection" is a concern, that you print out the products page in question and take it to them. Simply show them the page and ask if they could possibly have a "problem" with that product before placing your order. If that agency has a special need or concern, then contact us telling us what it is. Possibly, we might be able to provide information for them, which will elevate their concerns.

   We only offer top quality products that are acceptable in most areas, but that is not to say that we can guarantee that your local governmental body will "pass" it.

   Whenever my R.O. system is recharging (such as after I fill a large container with the filtered water) the air gap filter makes a gurgling and sucking sound. Is this normal? Noise from a Reverse Osmosis faucet air gap is normal and to be expected. Wastewater is draining and so noise from the water passing through the air gap cannot be eliminated totally. Shortening your tubing as much as possible should help diminish the noise to the lowest sound level possible. Please understand that the air gap is a kind of back-flow prevention device for your safety and so we never recommend bypassing it.

   My existing RO seems to work but when I want to get 3 gallons of water all at once it won't do it. Is this normal?

   Most residential RO systems come with a 2.5 (rated) gallon (or smaller) storage tank. Most won't hold that much water (this will vary with pressures) but once your RO has filled that tank you should get at least one gallon of water from it.
   To increase the amount of water that you can get at once, you can buy (and install) an additional RO water storage tank. We carry various sizes. Contact us with your specific requirements.

   Must I get a permit to install a Reverse Osmosis system?

   It depends on your local plumbing codes and rules. Since we ship to so many different areas we simply can not "keep up" with the latest local and state laws. If there is any question, we recommend that you contact your local code enforcement governmental bodies to be sure of the laws concerning reverse osmosis in your area before purchasing.

   From your experience, do you have any additional reverse osmosis installation tips or hints?

   With any brand of RO system that has a carbon filter ahead of the membrane, we recommend that you disconnect the membrane and run the water through the carbon filter initially for at least five to ten minutes. Most carbon filters will dump some carbon at first and this can foul your membrane. Do this whenever you replace the carbon filter as well and you will save yourself some potential grief.

   What does carbon CTO stand for?

   Carbon taste and odor.

   What are some of the additional benefits that a third pre-filter might provide (comparing the two filter models to the three filter model)?

   More carbon contact time, more chemical removal, better taste and odor removal.

   We also get this question a lot (in relationship to the question that we just answered):

   Is buying the three filter unit 'worth' the extra money? It is if your inlet water is really of very poor quality. It is if you can afford to have the 'best'.

   How often should I replace my filters and membrane?

   This is a very common (and difficult to answer) question. It depends a lot on your water conditions, water quality and your usage. In no case should you keep the filters longer than a year. The recommended changing interval is every six months. RO membranes can last up to two years, depending on water hardness. The harder the water, the quicker the membrane will fail.

   While I am buying an RO system from you should I order an extra membrane and carbon filters?

   Most companies will not mention this (or do not know) but RO membranes and carbon filters have a shelf life. We highly recommend that you buy your carbon filters and RO membranes right before installing them. Do not purchase extras until you need them.

   What are the dimensions of the 2.5 gallon storage tanks?

   The storage tanks are approximately 11" in diameter and approximately 15" tall.

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