ro unit

[DJ88]

You can go to a water supply store and get a home use RO. I paid $320 for a 24 GPD RO plus another $100 for the DI and get water that is rated clean for human consumption where the Kent isn't. As well with once it is time to change the membrane you can get it to run 35GPD.

Keep in mind the prices I had were with a discount. Check around. images/smiles/icon_smile.gif you never know what you may find.

If there is an Andrew Sheret's on the mainland check with them. That is where I ordered mine from.

I am using an AQUA FLO. unit.. works great.

[ 13 August 2001: Message edited by: DJ88 ]

[titus]

Hello,

FYI, SpectraPure's RO unit utlize 0.5 micron membranes. Kent Marines' are no where near that.

Titus

[reefburnaby]

I don't think RO/DIed water is safe for human consumption. Usually, UV sterlizer is required for human consumption to prevent nasty bacteria from entering your drinkable water. It has been known that some bacteria can live in RO if the RO is not flushed/cleaned periodically.....

Go for a good RO/DI water filter for good clean water. DI is important because it will remove any metals/phosphates/silicates that the RO missed.

35 GPD should be fine for your tank.

[DJ88]

RO is safe to drink. Kent RO/DI's are not for human comsumption. Brands manufactured for that use are. If they weren't they would not be for sale for installation in your home. images/smiles/icon_smile.gif

On our ships at sea(Navy) instead of using evaporators the newer frigates use massive RO units. enough to supply 225 men/women with clean water no matter where they are, each and every day. Normally only one is run at a time. No need for the amounts that are produced by two of them running.

images/smiles/icon_smile.gif

[farmerjo90]

I need on of these too. Which one should I get? 35 gph ...60 gph for a 180 gallon. I imagine KEnt marine are the only kind to get.

[terryp01]

I would suggest a RO unit that will suit your tank size. I use a 35 gpd and have a 90 gallon, 180 gallon and 9 - 20 gallons. Depending on your water change needs and top off, a 35 would be sufficient.

I live in the warmer climate and get about 20 gallons a day of evaporation.

[reefburnaby]

Hello,

Most household ROs are based on TFC membrane and they require non-chlorinated water to work reliable (the membrane has a tendency to self destruct with chlorinated water). This is why water must pass through a carbon block before it goes to the TFC and it is one of the reasons why we have to replace it fairly periodically)

Most RO membranes can filter out the large viruses and bacteria from the water. However, if the viruses/bacteria get trapped in the RO membrane, there is nothing to kill them. Remember, the city puts chlorine to kill these viruses, but we removed them to protect our TFC. Since our RO water is so clean, the bacteria/viruses should starve and die ? Nope...RO water still has tiny amounts of nutrients and it is sufficent for the bacteria/viruses to grow. After a couple of months, your TFC would be infested with viruses/bacteria and contaminate your filtered water.

However, since we add salt to our filtered water, most of these bacteria/viruses should die because most freshwater bacteria/viruses can not survive in salt water conditions. This is equivalent to freshwater dipping our saltwater friends.

The other common form of RO is based on CTA -- and it works with chlorinated water. But the problem with CTA is they are not as good at filtering water as TFC (higher percentage of phosphates pass through and etc) -- see Kent's website for details.

What to do ? Most people recommend placing a UV sterlizer at the last stage of the RO water filtering process. UV will kill most bacteria in the ROed water (not perfect though). Have you bought RO water from the store (say, Superstore ?) They are ROed, but they have a UV sterilizer at the end.

Want some more proof - Spectrapure sells a good product -- so why would they sell one of these :
http://www.spectrapure.com/kits_p2.htm http://www.purewaterexpress.com/faq.htm#7 http://www.actwin.com/fish/aquatic-plants/month.9701/msg00335.html

So...if you are comfortable with drinking RO water (that could have bacteria in it), then bottoms up. If you must drink RO only water, most manufacturers recommend that you disinfect your RO filtration system once in a while. For drinking water, I'll stick with RO + UV or boiled water....

I am not a water expert, but due to the line of work I am in...my health is extremely important.

Titus, most RO membranes can filter down to 0.0001 microns, so I am not sure what you are refering to. Also, Kent sells a floss/carbon filter that works down to 1 micron -- so why bother with a 0.5 micron RO filter ?

[DJ88]

Hi there,
I had a big post explaining how the RO works and such but lost it when my computer hiccupped grrr..

I have made a small image to help with this discussion.

I understand your concerns about bacteria and contaminants entering your purified water. With all the stuff going on these days with driking water it is bound to come up

You seem to think that the purified water comes in contact with teh pre filtration side of the Membrane. It doesn't. Save you having a tear in the membrane. With proper use and maintenance this shouldn't happen. The purified water never passes through any of the parts of the system on the dirty(or pre-filtering) side. after it passes through the RO membrane it is not allowed to be forced back through the membrane due to a check valve in place to stop this.

http://members.home.net/darren0469/ro.jpg


To tap water enters the pre filter, pre carbon then to the RO membrane. Once it is forced through the membrane the bacteria etc remains on that side of the system. If you do not check and replace the parts of this system then you can have the contaminants enter the purified side. I know that I make sure that all my systems with my reef are working properly. I one fashion or another. This is no different.

I have been in the navy for 11 years and the RO systems used on board the newer frigates for water purification are a great system. In my 11 years I have never heard of any problems or anyone getting sick due to water on board. When we enter into a foreign port where the water quality is suspect the water supplied is passed through the ship's own RO system. I have drank many many gallons of that water over the years. We did that in Thailand and other ports they weren't quite positive about the water quality. I have sailed on three of those frigates and have close friends on all the others.

I still say that they are safe. Yes, you should check and verify that your system is working properly. And that you do proper maintenance. That is a given. But I would much rather drink the water coming out of that filter than what is coming out of the taps. Even with the cities working to keep our water clean for human comsumption look how many cities have problems and have to shut off the water. The RO filter is an added protection in my eyes. Use it properly and it provides you with an added level of security.

I can see Mr Bingams concerns but once again it comes down to keeping your equipment working properly. He even stated that. Keep an eye on it. As for the UV and the Tank Sterilizer I don't see them adding anything more. Once again unless you have misused or over extended your RO membrane the particles and bacteria will remain on the pre filtration side of the unit. They are selling these devices by playing on peoples fears of getting bad water. To make an extra buck. If you want those. go for it. After seeing RO systems in use for a few years, I'll trust what I am using. And keep it in good shape. Just like any other investment I make.

If there were problems with these systems you would hear about it. So many people are ready to sue each other due to false claims etc. I know for a fact there are people out there who aren't as fastidious about the maintenance of these things or anything and you don't hear abotu anyone getting ill with the mis-use. Once again I will trust what I have experience with and used for a long time.

[titus]

Hello reefburnaby,

Kent's website state the membrane micron size for their RO system "as it is". I don't bother to look it up again but I remember it is larger than what SpectraPure uses.

And I agree with Darren. The bateria would mostly have been killed from the chlorine.

Titus

[FlameAngel]

RO's are used basically for one thing and that is to remove nutrients from the water such as phosphates and nitrates especially.
and that's what they do.

As for most of us (on city water) he are fairly blest. I've contacted the local water dept, for an analysis of the water. It's very good. Yet I still use RO.

Unless I'm living in Angola or goodness knows where, I'll never invest in a sep UV just for water, b/c for what we do. It isn't necessary.

FlameAngel

[gerowe]

I have been very happy with an AquaFX 100gpd that seems to me better built than a Kent RO I've used in the past. The latter, by the way, never lived up to its rated output, whereas the AquaFX has exceeded its rating even though I do not use warm water, which is supposed to make the unit more efficient. The AquaFX is also generally less expensive, I think. The one I have is only the standard 3-stage RO, but they sell 4 and 5 stage RO-DI units as well.

George