Reverse osmosis - where to buy

  • Get the NEW AquariaCentral iOS app --> http://itunes.apple.com/app/id1227181058 // Android version will be out soon!

gardiner

AC Members
Oct 9, 2007
7
0
0
I traded in my FW fish for salt (literally), but now I need water. My LFS is too far away to lug back 55gal, unless I want to buy 10 more 5gal containers.

I learned how RO/DI (reverse osmosis and deionization) works from Wet Web Media, all except for the most important details.

How can I tell if I need RO/DI filtration? My tap water reads about 10ppm each of nitrates and phosphates. What other tests should I do? Do I need a TDS meter? My local water quality report (municipal well water at zip 31768) is surprisingly uninformative...they don't even mention phosphates, nor do they indicate whether they use chlorine vs. chloramines. My Jungle QuickDip in the tap water reads about 300ppm total hardness, 100ppm total alkalinity, and 6.5pH.

Where should I buy an RO/DI unit? Some of the DI units look like tiny add-ons, while others are full-sized. Do I need a separate sediment filter, or can the carbon filter serve the same purpose? Do I need 2 carbon filters? Do any of you have recommendations?

Airwaterice.com 5-stage Typhoon $150
Melevsreef.com 5-stage $170
Aquatictech.com 4-stage 4-stage $161
Drsfostersmith.com 4-stage $165
Thefilterguys.biz 5-stage $135

P.S. My goal is a FOWLR tank...no interest in corals.
 
Last edited:

Grins

Girl Reefer...we do exist
May 1, 2007
10,449
0
0
58
Charlotte, NC
With the tests you've already run I'd say you need a unit. I highly recommend the TyphoonIII (comes with a TDS meter) , and have heard good things too about the units from Melev and the The Filter Guys. You'll do well with any of those.
 

fsn77

AC Moderators
Staff member
Feb 22, 2006
3,076
2
38
SC
I have the unit that's available from melevsreef and really like it. Although, I must say that the price has gone up since I bought mine... I'm not sure that I'd pay $170 for it considering some of the units available from other retailers, including my favorite place to buy replacement filter cartridges, thefilterguys.

While 10ppm nitrates is not horrible for a FOWLR, 10ppm phosphates could be a real problem. It takes far less phosphates to cause an algae problem than it does nitrates, and 10ppm phosphates is a lot.

A TDS meter is good to have. It can tell you how efficient your RO or RO/DI unit is at purifying the water, which can be an indication of when it's time to change filter cartridges or even the RO membrane (membrane gets changed far less often).

Having a sediment filter is a good idea. Even though carbon blocks are available with the same micron rating, any sediment that clogs the carbon block reduces the surface area contact of the water with the carbon block, which reduces the overall effectiveness of the carbon block at removing the impurities it's designed to remove.

If there's any chance of chloramines in your tap water, it's best to have 2 carbon blocks. Chloramines are harder to break down and remove than chlorine, and since RO membranes can be damaged by chloramines, it's better to be safe than sorry and have 2 carbon blocks to make sure the chloramines can be handled before reaching the RO membrane.

If I was going to buy a new RO/DI unit, I'd buy one from thefilterguys. I would buy the $160.00 - OCEAN WAVE+ FIVE STAGE 75 GPD RO/DI and add-on a pressure gauge (I'm not a fan of inline TDS meters... more of a pain to clean). A pressure gauge is also good for letting you know when the cartridges are clogging when placed between the last carbon block and the RO membrane. The reason I would buy this over the $135 unit thefilterguys sells is because of the DI cartridge. Horizontal DI cartridges contain less DI resin and consequently require more frequent replacement than the 10" verticle DI cartridges.

I hope that helps!
 

ahdonline

AC Members
Dec 11, 2006
60
0
0
Pittsburgh (Freedom)
i recommend thefilterguys.biz best all around service you can get that I have found to date. I agree that ebay is cheap but the two i bought from there lasted less than a year. I have had both the basic, and oceanreef+1 from the filter guys. Im am currently using the oceanreef+1 and its been great. You will have to be careful of your water pressure, being on city water you should be fine but if not that can get expensive also.

As much money as i have spent on RO/DI units i wish i would have just spent the 200$ up front from filterguys and been done with it.
 

Amphiprion

Contain the Excitement...
Feb 14, 2007
5,776
0
0
Mobile, Alabama
Real Name
Andrew
I would stick to thefilterguys, airwaterice, or melevsreef units. They are roughly the same, with some minor differences or extras, but all are good. I would choose the one that fits into your budget the best out of those and gives you enough features to be convenient for your circumstances. In my case, it was airwaterice, but I have also ordered replacements from thefilterguys.
 

clown-lover

AC Members
May 26, 2007
2,448
0
36
Fargo, ND
Agree with all of the above.. However theFilterGuyz are my next state neighbors.. Really good bunch of guys to deal with.. Their online form wouldn't let me cross ship to my work address but with a simple call it was taken care of.. Can't say enough good about these guys.
 

gardiner

AC Members
Oct 9, 2007
7
0
0
Thanks for the responses, guys (and grins). Exactly on point with the info I needed.

FWIW, I looked up some definitions that were fuzzy in my head.

Total dissolved solids[FONT=Verdana, Arial, Helvetica, sans-serif] are minerals, salts, metals, or ions. This includes anything besides suspended solids, such as wood pulp.[/FONT][FONT=Verdana, Arial, Helvetica, sans-serif] The TDS is the total positive and negative ions.

[/FONT]General Hardness measures positive ions like calcium and magnesium.

Carbonate Hardness measures negative ions like bicarbonate and carbonate. These buffering ions cause alkalinity.

[FONT=Verdana,Arial,Helvetica,sans-serif]Alkalinity[/FONT] is water's ability to neutralize acid without changing the pH. Since fish add acid to water and then are hurt by the acid, you want some alkalinity to stop the acidification.

Erm, a question...my brief research shows
Carbonate hardness to be the same as Alkalinity. Is that correct (at least for simple aquarium chemistry)?

So, couldn't I duplicate the functionality of a TDS meter by just using a test strip to measure General hardness and Carbonate hardness, and then adding them together?
 
Last edited:

Amphiprion

Contain the Excitement...
Feb 14, 2007
5,776
0
0
Mobile, Alabama
Real Name
Andrew
Yes, it is essentially the same (because carbonate alkalinity has by far the largest impact on overall alkalinity, alkalinity can be effectively treated as solely influenced by carbonate hardness.

The answer to the second question is no. There are too many other dissolved compounds to try to measure that have nothing to do with hardness (minus phosphate). TDS encompasses all dissolved solids and is, therefore, a more effective measure of purity.
 

gardiner

AC Members
Oct 9, 2007
7
0
0
OK, I see. This is great, being able to get answers from ppl who know their stuff. Hopefully other ppl had my same questions.

On that note...How can I tell whether my city is using chlorine or chloramines? And why do I need so much chlorine filtration for SW, when for FW it was sufficient to simply add a few drops of StressCoat?
 
Last edited:
zoomed.com
hikariusa.com
aqaimports.com
Store