Which RO/DI Unit to buy?

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flugelnuss

Clownfish
Joined
Jun 22, 2004
Messages
160
Location
West Seattle
I'm tired of lugging buckets of water from the market or LFS. I did ok enough on ebay to afford to spend around $200 on a RO/DI Unit.

I don't have very much plumbing experience and we are planning on moving in 6 months to a year, so I don't want to install it permanently. Also, we are limited in space as we live in a 570 sq. foot condo. Space is a luxury for us! I know what a unit looks like, but have never seen an installation of a unit. I hear that it is pretty easy, but again, I am a plumbing novice.

I am looking at a 5 stage unit from airwaterice.com called the typhoon III. a couple of guys on RC have recommended it and said that the owner of the website/company is a RC member and will include a float valve and a TDS meter along with the Typhoon III if you mention RC. That unit is running for $199 plus shipping.

I need some advice on if this is a good unit or not, and what other units everyone else has/have had experience with.

We have a 46g main and are building a 29g frag tank. We also have a 10g QT. I'm thinking that maybe a 50gpd unit would be enough.

Thanks in advance. I don't want to jump into this purchase without reviews and recommendations.

Jeff
 
I just got a Spectrapure unit which is supposed to be the best there is out there. I got mine from www.acropora.net and its a 60gpd model.. It works great and the tests I have prove it.. :)
 
I originally got the standard 100 GPD Typhoon from “Air Water Ice” that came with the Dow FilmTec TW30-1812-100 membrane. The typhoon is a nice made unit! However IMO there customer service is not that good!

I would avoid getting any RO unit with the Dow FilmTec 100GPD Membrane (TW30-1812-100) This is the same membrane that a lot of RO Vendors & E-Bay suppliers are using & it only has a 90% rejection rate, verses a true RO membrane which will have a 98% to 99% rejection rate. In fact Dow’s own Web Site calls it a “High flow 100 gallon per day drinking water element”. Not a RO element! On the other hand the 75GPD & under membranes are called a Home drinking water “RO elements”.
I replaced the 100gpd membrane with a high rejection rate 75GPD membrane & the difference is like day & night!
In my opinion I would go with either one of these vendors!
Aqua FX
ARS
Buckeye Field Supply
 
I bought one off Ebay from Aquasafe for way less than 200 bones and I love it. It works great for me.
 
Santawas Really Nice This Year I Just Bought A New 6 Stage Ro/di 110 Gpd For 120.00 From General Water Mfg. It Was On A Promo That Included Shipping They Sent It On Fri And I Recieved It On Mon.
 
Like snobanker I have the aquasafe unit from e-bay. 6 stage, for 120$ with float valve, with check valve, with 3 extra deionzation refills. Metal braquet to hold containers. It is awesome. Takes TDS from 240-270 to 0 tds. Makes lots of water. For under 200, you could get the extra pack of prefilters 4 of all filters and a box of 12 deionzation resin. 100 gpd. they are called aquasafesystems on ebay. Really nice people and they will help you. HTH Steve
 
Interesting, I have the typhoon from airwaterice.com and have loved it. I had a good experience with their customer service, so no complaints here.

These days you can find comparable RO/DI units all over the web, with just the basics, for $100 or less (check ebay). Obviously buying from a company allows the propencity for better customer service than buying on ebay, so it depends on what you value I suppose...

Take er easy
Scott T.
 
flugelnuss said:
I'm tired of lugging buckets of water from the market or LFS. I did ok enough on ebay to afford to spend around $200 on a RO/DI Unit.

Jeff
You might want to borrow a TDS meter and check your water before spending lots of money on a RO/DI unit. My water (Seattle, U-district) generally runs about 30PPM straight out of the tap. I get down to 0 to 1 with just RO. I've toyed with the idea of either getting a DI-only unit (to avoid all the wasted water with RO) or even just running the tap water through a particle filter and carbon only. Unfortunately, I spent the money on a RO-unit because everybody said to, before acutally checking my Water. Now that I have the RO, I use it, but ...
 
I am torn on the price difference. I would love to save the extra $100, however, I am getting so much conflicting information. I guess I could include the TDS meter in my $200 budget.

I used to use tap in the very beginning, but like dnjan, have been told by 99% of the reefing community that RO/DI water is a must.

Any other recommendations? Why should I go with the more expensive units like Spectrapure or Kent Marine over the cheaper non-brand name ones? Thanks guys. I consider your knowledge & experience to be priceless.
 
It Seems One Thing Seems Clear If You Don't Know What Your Tap Water Contains.than An Ro/di Would Be Smart. The Water That Comes Out Of Tap Changes Costantly. Most Municapal Water Sources Come From Many Diffrent Sources And Rain And Lack Of Rain And Pipe Conditions And Various Treatments Make Tap Water Most Unstable. Best Bet Check Out Ebay See What They Have To Offer. Compare To Prices Of Others. Even A Bare Bone Ro Is Better Than Nothing.
 
Check it out, I was talking to one of the moderators here about ro units. He works for a company that makes ro membranes, the jist of the conversation as I understood it was there are only two manufacturers of ro membranes, if you get one made for a reef system you will be happy. The real question is how are the bracket, containers, and filter cartridges made. I have and use the aquasafe system. I know others on here use it, and danny just got one too. It works just as good as one that costs 300$ and it only cost 120 with float valve, check valve, and auto shutoff valve. It is impossible to get any better than a output of O tds. I mean what else can you do? LOL
the only down sides to this system I could find. The containers are not clear but for 180$ saved I dont care, one other is the same with any refillable deionzation cannister, it sits sideways instead of up and down. As the deion shrinks in size it allows the water to pass through less deion resien. I am going to mount the braquet for the cartridge up and down hopefully solving that problem.
It is however better in my opinon than the one that use a slip in cartridge that costs more to replace.
Only my opinons. I hope it helps you. STEVE
 
How about the GPD rating? From what I have read, the water gets less contact time in the carbon and DI stages in high-GPD units than low-GPD units. I don't need 100 GPD either.
 
The flip side of that coin, is this. If your membrane is rated for 50 gpd and flows 25 gpd, would it last as long as a membrane rated for 100 gpd that flows 25 gpd?
It is my understanding to go for the highest flow rate per day within reason and not use the full capacity than to get one that is rater for less seeing as the price is so similar. The flow speed through the carbon and deion is not a factor if the end result is 0 tds vs 0 tds. Again just my opinions. Its your money and you should buy what you want. I am just telling what I have and how it performs for me. I do tank maintence for my customers and use lots and lots of ro water. I used to buy it from the LFS, at 50 cent a gallon. Now I have many times over, been repaid for my rodi unit, and it saves me the time of going to the store. If it broke tomorrow I would buy the same one and that is a good a recomendation as I can give. HTH STEVE
 
One thing to also consider when figuring out what size GPH unit to buy is your waters temp! Most membranes are rated at 65~70 degrees at 60 PSI water pressure. When the water temp drops the membrane will shrink reducing the output. For every degree below 70 you will lose about 1.3% output! So in my case here in MI my water temp is at 42 degrees during the winter so my 75GPD membrane only makes around 35GPD.
 
I'm not trying to discount the aquasafe model. I am actually leaning towards it right now. Someone from RC said this,

It all depends who you buy from. Some ppl will say the more expensives ones are far bettter. Some say the cheap ones on ebay are as good or if not better. But if you have a tds of 0 . And the membranes last. I see no reason to pay more.
It is making more and more sense as we discuss it. I am not a brand junkie by any means, but I'd like to make sure that I purchase this one unit and not have to "upgrade" to another unit in the future just because I bought the cheaper unit just to save a few bucks. I'm sure you can understand my thought process here as we have all bought cheaper equipment for this hobby at one point, only to shell out more for better equipment once we've realized that we can't cut corners on certain things (i.e. skimmer & lighting in my case!).

I've always kind of lived by the saying, "you get what you pay for." I just want to be 100% positive before making this purchase.
 
flugelnuss said:
But if you have a tds of 0 . And the membranes last. I see no reason to pay more.
Yea you will get 0 TDS after the DI! But if the membrane is only rejecting 90% the DI will be used up really fast!

I originally got the standard 100 GPD Typhoon that came with the Tw30-1812-100 membrane. I used the RO/DI unit for about six months & still had a bad hair algae problem. I just figured that it had to be from something else? After doing a lot of testing & ruling things out I ended up back at the RO/DI water! That’s when I figured out that something was wrong?

The TDS of my city water is only 125 ppm. Which is pretty good compared to others that I have heard about! I tested my city water & it had 3.5 mg/l Phosphates & the Silicate was off the scale. After the RO Membrane (before the DI) I still got a reading of over 2 mg/l PO4! This made me start to do some checking around & that’s what lead me to find out that the 100 GPD Dow FilmTec Membrane only has a 90% rejection rate versus a true RO membrane that has a rejection rate of 98% to 99%

After a lot of haggling & several flame wars on RC with Walter from Air Water & Ice I managed to get the membrane replaced with the High rejection rate 75 GPD Membrane. My test readings after the RO with the new membrane are now 0.5 PO4! Still a little higher than I like but the DI takes care of that.

In my case I also found out that my city water is treated with Silicate & Phosphorus acid to treat our water lines for rust & corrosion, That’s the reason for me having the high PO4 readings. My DI filters would only last about 150 gallons before with the old 100 GPD membrane. Since I switched to the 75GPD high rejection membrane I now get over 400 gallons from the DI.
 
I have had the same 25gpd membrane for the past 4.5+ years. Still 0 to 1 TDS (no DI, just RO). My best estimate is that I have produced close to 2,000 gallons of 0 to 1 TDS RO water. Instead of a higher capacity membrane, I would go for a good float switch system. And come up with something positive to do with the waste water. I currently have my waste going outside to a couple of rose bushes.
 
I'm even more confused now than I was yesterday. I really don't want to go through the hassle of purchasing something that I will have to change out a part. Is that what I would have to do if I bought the cheaper unit off of ebay?

I guess the ultimately the original question has to be asked. Is it worth it to get the more expensive brand name units?
 
OK, if you buy the reef unit from aquasafe on ebay for 120$ you will recieve, a 100 gpd ro membrane that will remove 99% of the stuff left in the water after the first 3 prefilters, a deion canister that will remove the last 1% and a post filter just for the heck of it. 6 stages. You will if you ask for it, recieve a good quality float switch and a automatic shut off valve so that when your unit fill the container it will automaticly shut off the water flow. It is the exact same ro membrane as you find in a unit that costs 300$ the only differnce is that the cannisters are not clear, why any body wants to look inside the canisters is beyond me anyway but thats another subject. Thats delivered to your house. 120$ it will make all the 0tds water you can use, when you are not using it, it will shut itself off untill you remove the water to make saltwater, then it will kick on and make more rodi water. It will do this for a very long time.
I am in no way asscoicated with the guy that owns the company. I am just a very happy customer, because of the customer service I have recieved, and seeing other units that cost more and dont do as good of a job.
So to answer your question, Is it worth it to get the more expensive brand name units. I would have to say no. A tds reading of 0 is 0 no matter how you cut it. If on the other hand you get a household NOT REEF ro unit that has had a deion cannister added You will be unhappy.
If you get a reef system off of ebay be carefull
Danny got one that costed more and was a peice of junk
Now he had to buy the aquasafe one and is very happy with as I am with mine.
I hope this helps you.
Steve
 
I Was The Same As You I Went Years Without An Ro/di I Really Didn't Know Much About Them. I Bought Those Aquarium Pharm Purifier. It Worked Well But It Would Leech Po4 Thru Before The Resin Would Change Color. And In Return I Used A Lot Of Phosphate Remover.
I Only Recently Priced Them And Went For It I Can't Complain 120.00 For A Six Stage Is Fantastic Specially Since It Retailed For 379.00 Ultimately It Is Up To You What You Buy And How Much You Spend Good Luck On Your Decision. Ask Yourself How Much Water Do I Need To Make At A Time. Even A 110 Gal A Day Ro Takes 6to8 Hours To Make 35 Gals Of Water. You Have Alreay Answered Some Of Your Questions
 

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