Buying a new R.O. Unit, which one should i chose?

With a raw water TDS or 627 yesterday I would eat DI resin like there is no tomorrow if I used a 90% rejection rate membrane like the Filter Direct units. With my 98% rejection rate membrane I registered 8 ppm TDS yesterday. If I had a 90% unit I would be seeing over 60. How long do you think resin would last me? I don't hear an answer!!!! You need to do your research.
 
<a href=showthread.php?s=&postid=6479388#post6479388 target=_blank>Originally posted</a> by lbrty9
The rejection rate argument is a wash... you're talking an 8% delta. IF we were making water for a nuclear powerplant or something, then fine... but it's a fish tank. As long as I wind up with 0 TDS, then I am happy and my tank is happy. I've been running mine for almost a year and a half and only had to change resin once and I don't think it really matters whether the cartridge is vertical or horizontal, as long as you get a good flow through it. The DI tube size is EXACTLY the same as all the other DI tunbes being mentioned (at least that I have looked at), so the increased useage argument doesn't wash either. SO the TDS meter is about $25 and I don't really see how you think a pressure gauge is necessary. So like I said, about $125 into the thing and it is perfect for keeping your tank happy, which is really the bottom line. All the other stuff you mentioned is just buying things which your fish and corals could really care less about.
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Rejection rate is not a wash. Its a fact. The DI on a filter direct unit is not nearly the same size as a www.airwaterice.com unit. The bottom line is the filter direct unit gets the job done for a short time and is cheaper to begin with. It by no means a good quality unit with any extra fetures. Its a cheap RO unit. It suites some people but i personally dont by the cheapest thing i find. Im not so sure but i think water is one of the 2 most important things in my tank. (the other being salt)
 
<a href=showthread.php?s=&postid=6480604#post6480604 target=_blank>Originally posted</a> by integlikewhoa
Rejection rate is not a wash. Its a fact. The DI on a filter direct unit is not nearly the same size as a www.airwaterice.com unit. The bottom line is the filter direct unit gets the job done for a short time and is cheaper to begin with. It by no means a good quality unit with any extra fetures. Its a cheap RO unit. It suites some people but i personally dont by the cheapest thing i find. Im not so sure but i think water is one of the 2 most important things in my tank. (the other being salt)
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Rejection rate is an issue at times, I just don't see it as an issue when making water for a fish tank. I've been running mine for about a year and a half and have noticed no issues with it. Works well and keeps my fish happy for less $$$. I bought me a nice Hippo Tang and Foxface Lo with the difference.

The AWI DI does look larger, but if my resin is lasting me from 9-12 months, it's just not that important.
 
<a href=showthread.php?s=&postid=6480325#post6480325 target=_blank>Originally posted</a> by AZDesertRat
With a raw water TDS or 627 yesterday I would eat DI resin like there is no tomorrow if I used a 90% rejection rate membrane like the Filter Direct units. With my 98% rejection rate membrane I registered 8 ppm TDS yesterday. If I had a 90% unit I would be seeing over 60. How long do you think resin would last me? I don't hear an answer!!!! You need to do your research.
Click to expand...

I have done my research, the result is a fliterdirect ro unit feeding my topoff water tank. Perhaps you would have been better served to spend that extra money on a whole house filter, that way your fish AND your family would have good water... Your call, but I'm prefectly happy with mine and only into it for $125.
 
<a href=showthread.php?s=&postid=6482597#post6482597 target=_blank>Originally posted</a> by lbrty9
I have done my research, the result is a fliterdirect ro unit feeding my topoff water tank. Perhaps you would have been better served to spend that extra money on a whole house filter, that way your fish AND your family would have good water... Your call, but I'm prefectly happy with mine and only into it for $125.
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There's no need to denigrate someone else's choice here..that's out of line. When you have demands for more water (a larger tank), the "cheaper" unit no longer becomes the "cheaper" unit over time. Rejection rates DO make a difference and are important to those people who do the math.

You get what you pay for.
 
<a href=showthread.php?s=&postid=6483058#post6483058 target=_blank>Originally posted</a> by javajaws
You get what you pay for.
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Exactly! Its like driving a geo metro and telling someone else that they shouldn't have bought a Lexus because the geo gets them to and from work just the same. It just don't have power windows but you can still manually roll them down. The other difference is the www.airwaterice.com unit is only 75.00 more and comes with a float valve for auto top off along with other things that add up to the same price anyways. The price of the tank is not cheap and 75.00 for a tank is nothing. That's less then my electrical bill for the tank alone a month.
 
<a href=showthread.php?s=&postid=6484321#post6484321 target=_blank>Originally posted</a> by The Reefer91
i'm trying to get a relatively cheap one, but don't want one that's low quality for a big tank(125g). so i shouldn't get the one from buckeye?
http://www.buckeyefieldsupply.com/showproducts.asp?Category=168&Sub=166
what would you suggest? i'm on a form of budget
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Just be sure to get the 75 GPD one...the 100 GPD is usually the 90% membrane. You might want to ask what accessories it comes with...by the time you add up a TDS meter (highly recommended), the hookup valves , tubing, etc. it may be more than a Typhoon III....and that comes with an additional filter stage as well. I don't think you'll go wrong with either...just don't look at price alone....you have to look at the total price to get up and running.
 
yeah..would it be cheaper to get a typhoon in the long run do you think? i know, i know, it's not all about price, but i am trying to not spend a ton of money on 1 piece of equipment
 
I'm not sure...the only "functional" differences (the only difference that would affect the cost after install) is the fact that the Typhoon has an extra filter stage before the RO unit. I can't quantitatively tell you how much that will affect the life of the RO membrane or your DI filter (especially when you count in replacement costs of the extra filter itself).
The 2 units probably also ship with difference micron sizes in their floss/carbon filters...not sure how you can count that in the equation or even if you should try.

Have you looked at shipping costs for both as well? That may tip you one way or another...
 
I'm not putting anybody down, I'm just trying to explain how I think spending the money for the more expensive unit is just an unnecessary waste of money with minimal return on the investment. No offense intended...
Why is it that every RO unit discussion seems to devolve into those who spent more money for the higher end units getting all offended when someebody points out that they could have met all the necessary objectives they need an RO unit for by getting the $100 filterdirect unit...
I'm just saying that my experience with the filterdirect unit has been good and it is more than satisfactory for making water for a fish tank.
 
In you case it may be satisfactory, you must have very good water to begin with. Do you happen to know you water quality especially TDS readings? I get tickled by people who say their DI resin lasts over a year when they are making 30 or 40 gallons per week and using a 90% nanofilter. What they do not realize is DI resin has a very finite capacity and when you exceed that capacity it begins to leach contaminants back into the treated water. A pound or 16 oz of DI resin will treat about 3000 total TDS
if I remember correctly so if your RO is putting out a TDS of 10 then you can expect to treat about 300 gallons of water before it is exhausted. Thats a scientific fact and you cannot change it, thats all it will hold. So with that in mind you see why the better membrane and the larger capacity and better flow design DI filter is a better deal. The vertical cartridges hold 24 oz of resin so they last longer than a 6 oz or even two 6 oz filters. By the same token you want to pass as clean a water as possible on to the DI so the better 98% rejection rate membrane is by far the better way to go.
If you took a unit like the Typhoon III, took away the pressure gauge and TDS meter(although some vendors provide a TDS meter), installed a less expensive membrane, removed the float valve, shipped it partially assembled with poor directions, installed lower quality pre and carbon filters and took away the additional full size canister and refillable cartridge you would have the units you are describing. But why? It will cost you much more in the long run and even in the short term to upgrade all the components to make it more efficient. Or you can spend more money on replacement resin, even in bulk you will soon have more money invested than what you would have spent in the beginning. It does not make sense to me to skimp on water quality.
We steer everyone to the best lighting, skimmers and other components, why not RO/DI?
 
OK, what's better? The 75gpd compact reefkeeper from airwaterice.com or the one from filterdirect? I was going to go with the one from filterdirect because it seemed like it had everything... it claims 98% rejection I believe.

If the one one from airwater ice really is all that better I will spend the extra $40 or so for it.

Does the one from airwaterice have the easy flush valve?
 
Zero TDS is not the gold standard of RO/DI.

All DIs will produce zero TDS. Itââ"šÂ¬Ã¢"žÂ¢s how you get there that counts.

You can use this and get zero TDS.

17101175.jpg


http://www.petsolutions.com/Tap+Water+Filter-I-17101175-I-.aspx

So why not use it? Itââ"šÂ¬Ã¢"žÂ¢s cheap.

Because it will become exhausted very quickly. You have to replace it every 50 ââ"šÂ¬Ã¢â‚¬Å“ 150 gallons

The purpose of a RO is to ââ"šÂ¬Ã…"œstrainââ"šÂ¬Ã‚ out as much as possible mechanically before the water gets to the DI.

What you need do is take the line loose that goes from the RO before it gets to the DI. Use a TDS meter to take the TDS of that water. Now take the TDS of your tap water. Subtract the RO output TDS from the tap TDS. Divide that number by the tap TDS. Multiply by 100 to get your membrane efficiency percent.

Example;

Tap = 300 TDS

After RO (going into the DI) = 6 TDS

300 ââ"šÂ¬Ã¢â‚¬Å“ 6 = 294
294 / 300 = .98

.98 X 100 = 98 %

The higher efficiency your RO membrane is, the less DI resin you will use.
 
<a href=showthread.php?s=&postid=6485454#post6485454 target=_blank>Originally posted</a> by leeweber85
the one from airwaterice doesnt look like it comes with a refillable DI filter.
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They all have replaceable DI cartridges. I don't think any of them are "refillable". The DI on the compact reefkeeper looks to be the smaller size...which should be OK if you don't need alot of water (have a smaller tank). The DI on the Typhoon models is full size.
 
BTW, does anyone know if airwaterice is running the special they used to run...1 free extra set of refill cartridges with a RO/DI unit? This was a great deal...you may want to call and ask.
 
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