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Discussion Starter · #1 ·
As some of you know, I'm running two multi-tank reef systems at Augsburg College, totalling something on the order of 650 gallons. These tanks are pretty much all uncovered, and needless to say, we go through a lot of topoff water (a good thing, since this is how I dose kalk).

Thus far, I have been using deionized water from our lab-grade deionizer. This unit supposedly produces very good quality water, but recharching/replacing the deionizing beds is not cheap, and we are running though DI water faster than ever. Making matters worse, the cost of our DI unit maintenance contract has just gone up.

I'm thinking an aquarium-grade RO unit for aquarium topoff would make a lot more sense, and would save us money. I think we are running through something like 9 gallons of topoff water a day (this might be a small overestimate).

Can any of you recommend a good RO unit to buy that would keep up with our topoff demand?

Are there any RO models/brands to avoid?

Finally, our water pressure in this part of Minneapolis is very high. Is this likely to cause problems in an RO unit? (as you can see, I have no direct experience with RO units!).

Thanks,
Bill
 

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I'm not positive because I have no experience in RO units either but I believe that high pressure is a good thing. I have read a few cases were people have had to buy pumps to increase the water pressure so that it is sufficient to run the RO unit. Anyone have anything to add to this? I am a little curious myself... I would like to invest in a RO unit hopefully in the near future (it gets rough going to the grocery store & LFS twice a week to buy water.) Anyway any recommendations on how big of a unti to buy? I have a 30 gallon, starting a 10 gallon, will eventually have a 40 gallon, and at some point in the future I hope to have a 120 or 125 (some where in that range.) As of right now my 30 evaps about 1/3 of a gallon a day or so. A 40 I would assume will do double that (maye even a full gallon) bacause of the amount of surface space and plus it will have MH on it and no lid the top (egg crate only if needed.) As far as the 10, I'm sure it will do less than the 30. As far as 120 or 125... I have no idea. But if Capman has 600+ gallons and only loses 9 a day I'm sure I'll be well below that.
 

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A goof
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I would say get about as big of an RO that you can afford. High pressure is better for RO as it would waste less water. We are going to give up our Kold_Sterile when we move from well water to city water and get a unit from here http://www.airwaterice.com/Reefkeeper Home Page.htm . I have heard many good things about this company.

HTH

Jon
 

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Trodder, get the biggest one you can. The 75gpd or 100gpd. It's as much about how much you use on a daily basis. You want a bigger unit for those times you need lots of water ( for example upgrade, or emergency water change. ) It's a bummer with a slow rated unit and takes a day or more to make your water when its an emergency.

I too agree on the airwaterice units. If I didn't already had myself they seem to be the best deal going. The $149 unit should be all you really need.

Also I don't get hung up on brands. Remember the actual membrane there are only a couple of manufacturers. All the cartridges such as DI/sediment/carbon are all standard and interchangeable so you can use what ever refill you want with them. I would also opt for the auto shutoff kit. It's worth the extra money if not already included. When I had an apartment and couldn't directly hook up the unit there were many nights were I forgot to turn it off and woke up to a wet kitchen floor.
 

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Discussion Starter · #7 ·
Thanks everyone.

Dirk,

Yes, I just sent you an e-mail on this. Payment should be arriving any time now. Sorry for my delay.


Others,

$149 for purchase of one of these units would pay for itself quickly....lab grade water deionizers (and regaular maintenance of these deionizers) are pretty pricy by comparison, and we really don't need ultra-pure lab grade water for our tanks.

How often do you typically end up replacing the membranes (and DI resin...I imagine there is a DI prefilter of some sort?)? Approximately what does this cost? (I know, frequency of replacement will be influenced by how much you use it).

Bill
 

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ditto on brand, etc

and ditto on LARGEST you can afford

I have a specturapure 160gpd

gives me about 5 gallons per hour, (if it DID give me 160gpd)

water temp affects your GPD, get a 24gpd RO/DI thinking you dont need that much, but if your water is very cold, your GPD can go down to 12gpd or even less, depending on temp of your water.

imagine getting 0.5 gallon per hour.

that emergency will NOT go away
 

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A goof
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Bill, I would recomend getting as many prefilters as you can, the prefilters are a lot cheaper and will keep the RO membrane lasting longer.

Jon
 

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The sediment filters ( $6 ) last me about 3 months before they turn real red from the iron. Carbon I change ever 4-6 months.
Membrane on average will run about 2-3 years before needing replaced. I use the DI resin from www.resindepot.com using 2 cartridges back to back and lasts about 4 months for me.

I used 5gpd in top off + about another 160g per month for water changes ( FW and SW tanks ) so about 310g a month of filtered water.
 

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I purchased a unit from the company Jon referred to as well (Air, Water and Ice, Inc) and thus far have been very pleased. I've heard good things about the Spectra Pure products as well although their a few more bucks then the Air, Water and Ice products for what I suspect is the same thing.
 

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Discussion Starter · #12 ·
Thanks everyone. This gives me a general idea to help me consider the best course of action.
 

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why is this RODI unit from SpectraPure almost $400, when this one from Aqua-Safe is only $100. Especially in light of David Grigor's comments on brand (not to get hung up on brand because they all probably use the same or similar filters) And given that the Aqua-Safe is a 6 stage while the Spectra-Pure is only 5 stage.
 

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I recently purchased the Aqusafe unit, and like it very much.I think the 6 stage 75gpd unit, TDS meter (cheap, but matches the much higher quality one we have at work), and a case of replacement cartridges, with shipping was around 200 bucks. Not a bad deal, IMO. It's not the fastest thing around, takes about 17 hours to fill my rubbermaid garbage can (33 gallons, I believe), but serves my purposes. I might consider getting a pressure pump at some point in time, which would help production, but that's a ways down on my wish list. And by the way, customer service was top-notch. I had e-mailed them about adding the replacement cartridges, and they tried to reply, but my ISP's spam filter kept refusing it. Called and talked to my wife at home (who didn't know what to tell them), and then me at work. Very pleasant to deal with.
 

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I bought mine off of Ebay from Water Purification Supplies I think he goes by wpsinfo and it has worked great for me, a five stage RO/DI 75 GPD for around a $100. It had the same DI as the one linked above on Ebay and it was pretty small so I bought a housing and a refillable cartdrige and have had not problems.
 
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