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purified RO wate question


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Hi all, I have a 1 gal pico tank that I am using RO water in.


I need to get more water and when I called a local grocery store she said right on the machine it says Purified Reverse Osmosis Water.


Is this stuff okay to use in my tank?


My first couple jugs came from the place I guy my corals from but I don't want to go up there just to get water, I don't think they would appreciate it as its a home based business.


A RO system is out of the question for such a small tank, which will be upgraded later on to no larger than a 3 gal for my ricordeas. Been there and done that with bigger tanks, staying small this time.


In the past I just used my tap water boiled it cooled it and conditioned it no issues but this time I have had some issues and really want to see the difference with RO water.


I would like to know what does the "purified" mean?

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Boiling tap water does absolutely nothing for removing TDS which is what you are trying to accomplish. RO by itself only does 90-98% of the treatment, the final polishing is done by the DI filter.


The only way to tell if the vending machine is any good or not is with a handheld TDS meter, I always recommend anyone purchasing water have one so they can see what they are getting. Vending machines are usually for drinking water and the TDS is what makes water taste good, minerals. Then most machines are not regulated by any healt departments so the water quality is hit and miss. If you must buy RO water, find a staffed water and ice type storefront where the owner or manager will usually test the TDS or conductivity in your presence. Most are proud of their water so take care of maintenance.


If you cannot find RO/DI my second choice would be distilled water, it can be had at any grocery or at WalMart and some have it in 2.5 to 3 gallon jugs. RO only would be my third choice andtap would not even be on my list, conditioned, boiled or not.

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Boiled tap water doesn't do anything except killing any potental bacteria in your tap water. It does not remove chlorine, heavy metals, silica, or dissolved organics (like nitrates, ammonia, phosphates, etc)... Water conditioner doesn't really help remove the chlorine or heavy metals, it just binds it easier but without any filtration, it'll still be present in the water...



Purified RO would remove the chlorine, heavy metals, and silicas. Though, it may not remove dissolved organics like phosphates and nitrates.


Hence, the DI stage would remove the rest of the dissolved organics and other contaminates the RO didn't catch.

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Well I did a lot of checking in my home town and RO/DI water is next to impossible to get here. Many stores have RO water, our Superstore here only has spring water as do a lot of other only have the spring water.


Safeway I talked to the managaer today said that their RO water filters are changed every Monday, there is nothing added to the RO water but they do not have the RO/DI even my sister in law who owns a water store here very seldom brings in the RO water as 90% of the water sold in my home town is for drinking and people like the spring water.


The manager of Safeway said there are 3 other reefers here in town that come and get water by the huge jugs at their store and never had an issue with it so I am doing to give it a try as they seem to be the most reputable here. A lot of other water outlets have their stations outside the buildings and when I asked how offer the filters are changed they could not answer that.


An RO/DI system will not happen in my home, I only have a very small tank and buying it is far better for me as I do not need very much at all. A 4L jug will last me quite sometime, but if on had a big system then I could see that cost of buying would be an issue.


I also asked about Distilled, that's hit and miss here as well. I guess this RO and RO/DI water is just not as popular here in my part of Canada as it is in the USA and other areas.

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RO will still have TDS, the amount will depend on how much was there to begin with and how efficient their RO is. I again recommend buying a handheld TDS meter before buying any water. You need to know what the quality is yourself and not take someone elses word for it. All it takes is one bad jug of water to wipe everything out. Test the water each time you buy it. The machines may have their sediment and carbon filters replaced weekly but neither removes TDS, the membrane does that and I guarantee you it does not get changed.


You can get a good temperature compensated handheld TDS meter online for $20-$25, the HM Digital TDS-3, TDS-4TM and AP-1 are all very good models. Stay away from the TDS-EZ, it is $5 cheaper but is not temperature compensated.


Water is the single largest ingredient in a reef tank and everything depends on its quality AND its stability. Until you can get a TDS meter use distilled water from WalMart with the purple cap jugs, this has been reported over and over as being very pure by those who use it.

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I used Poland Springs distilled for about a year, it always measured 0 TDS when I tested it. There are too many variables with RO water, water pressure, temperature, condition of the pre-filters and membrane. A place/machine that is good today might not be tomorrow. You should be safe with distilled, but testing it is still a good idea.

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