RO/DI Unit ?

[Riderc82]

Well I'm thinking of buying a RO/DI unit I'm just trying to decide if it is worth it.  Currently I have three five gallon water bottles that I take to the store with me.  On average my system evaporates about five gallons a week and I do a five gallon water change a week, so basically I only use 10 gallons of water a week.  The grocery store I shop at sells five gallon refills for $1.85 so I pay $3.70 a week.  So 52 weeks x 3.70 = $192.40.  If I buy a RO/DI unit it looks like I should be prepared to pay at least $175.  It appears that the carbon filter could possible need to be replaced twice a year so that would set me back $20, the sediment filter would be about $25 twice a year so $50 and the RO membrane would be about $40 once a year.  So does this sound about right $20+$25+$50=$95 a year but I forgot the DI resin so that would be another $20 for a grand total of $115 a year for filters.  Does this sound about right for 10-15 gallons of RO/DI water?  What LFS stores sell RO/DI water and how much do they charge maybe I would be better off to go this route.

[UDJustin]

what you really need to look at as far as where you buy from now is how they distill it(I take it it is distilled water you are buying) also how often, if you intend to buy it from lfs, do they swap out the filters, because I can tell you some lfs dont do it very often. I work at Joel's he is very intent on keeping the filter media swapped out and does it on a regular basis we also test it from time to time with a tds meter. I dont believe at this time Joel sells his water, maybe its something you could talk to him about. Thats my two cents about ro/di units yes they can cost some money up front but unless your testing the water your getting your tap maybe just as good.

[Riderc82]

I need to invest in a TDS meter I've always been curious what the water at the store would test.  the only algae i have in my tank is on the overflow so I guess it probably isn't that bad, J.L. (whoever that is) test the water at the grocery every week    at least that is what the sticker says.

[verper]

I think your estimates are off a little.  First, the RO membrane can last up to 5 years, so scratch off $40.  Second, the sediment filters are usually cheaper than the carbon filter (which you have about right) so deduct another $10.  Depending on your source water's TDS, the DI resin can cost less or more than your estimate.  $20 + $15 +/- $20 = $55ish.  Now that doesn't take in the cost of more source water use (4:1) to make the RO/DI.

I will say that udjustin is correct in saying that you have to be carefull where you buy RO from.  I tested many places back before I had a RO/DI unit and at all of the places I tested, the TDS were not anywhere near 0.  I ended up buying distilled water from walmart until I could afford a RO/DI unit.  But the gallon jugs are only good for smaller tanks like the NanoCube I had.

I would think that the water out of the machine at the grocery would only be RO, not RO/DI.  Could be wrong.

[Hunter21]

Rider, what store are you buying your water from? This has sparked a big debate in my house as well...as I've been saying I want to just invest in an ro/di system but my parents are saying just buy the 5 gallon jugs water from lowes or even walmart.

[Riderc82]

I live near Bellbrook so I either get it from Cub Foods or Walmart.  Cub Foods has a nicer looking machine it says it has two carbon filters, RO and UV.  Each week it has a sticker on it saying it was tested for quality.  I have been considering buying a RO/DI because it would be nice if I ever had a crash but buying/changing/testing the unit just about doesn't seem worth it for as little water I use.  I was hoping someone would give me some arguments for buying a unit.  ***EDIT*** I didn't see Verpers comment the water isn't DI out of the machine.  Thanks for your estimates on the filters I just started reading about them today so for 10 gallons of water I am going to use 40 gallons source isn't there a way to have the waste water go somewhere else like the washer since the RO/DI unit would be in the closet with the washer and dryer?

[verper]

I think it should be the first item you should buy for a reef tank.  Even before purchasing a tank.  I feel its that important, but of course, it never works that way.     Your water quality will get you sooner or later.  It's much easier to keep things out of a tank than it is to get them back out once added.  Your Cub Food water could be anywhere between 10 and 100 ppm TDS because it doesn't go through a DI stage.  This article is very good at explaining what could be in that 10 -100 ppm:

http://www.reefkeeping.com/issues/2005-05/rhf/index.php

Buying the unit is your main cost.  I ran my RO/DI for a year without changing any filters before I started upping water usage for my 120 gal.  The testing is just sticking a TDS meter in the water every so often.

[Riderc82]

Ok i'm sold, so where should I buy one?  Verper do you just let the waste water go down the drain or do you use it to water plants etc....  What should I look for in a system?  It looks like E-bay has some decent systems but if I could pay a little more and get something of equal quality locally that would be as good.  here's the one I was looking at on E-bay   http://cgi.ebay.com/Zero-ppm-RO-2-DI-Aquarium-Reverse-Osmosis-Water-Filter_W0QQitemZ110273017160QQcmdZViewItem?hash=item110273017160&_trksid=p3286.m14.l1318

[Hunter21]

is it possible to sustain a tank on the water from the store?

[Riderc82]

I've been doing it for three years now but I must be lucky I haven't had to many problems at all.

[Hunter21]

Like I was saying, that's what my parents are wanting me to use because it's not my house and dad isn't going to hook up a unit even if I bought it. So that's why I ask if it's possible to sustain a tank on it. how many gallons is your tank and what sorta setup is it? I'm setting up a 29 gallon and they figured it wouldn't be that many trips to the store to buy water each week.

[Riderc82]

I have a 90 gallon with a 30 gallon sump, I have a Octopus NW 200, three #3 Koralia powerheads and one #4 Koralia.  My return pump is a Mag 5.  For lighting I have 2x175 Metal Halides.  I have a mixed reef but In the last couple of months I have been working toward going mainly SPS.   

[Hunter21]

and you ran all that on water from the store??? 

[Joel]

I have a few things to add;

The rejection rate of RO water prepared for drinking water is often pretty low compared to aquarium or research grade water. With this type of water, taste is a consideration so some minerals are aloud to remain in the product. Might not be a bad thing for drinking water but can be a major problem for aquarium water. I Agree that testing the TDS is a good idea, I like to see 0 to single digits PPM, I very seriously doubt that drinking water will be that pure. Distilled water is risky as well because of how it is prepared. Many company's prepare distilled water using copper tubing and as a result, their product water can contain copper.

If a person is in the market for an RO unit, be cautious of the cheepie one's available. They often are wasteful and produce lower quality water. It has been my experience that the dow filmtec RO membrane rated at 50 GPD is one of the better ones to buy. I realize that not every one needs a 50 GPD unit but it is much less wasteful when compared to smaller GPD membranes and has consistently made better quality water when compared to other brands that I have used. Just about any RO Unit will house this membrane if a person wanted to use it, just be sure to get the correct flow restricted for it.  Also, I notice the term "install" in a earlier post regarding an RO unit. They (ro units) don't necessarily need to be installed. Most my customers just hook it up to their sink to fill a container and store it when not in use. There is no need or reason for permanent installation.

Swapping out the sediment trap & carbon block regularly can significantly extend the life of your RO membrane and your DI resin. As per how often to replace the sediment trap & Carbon...that's a good question with no one correct answer. It all boils down to, how bad is the source water. Really nasty water might clog a sediment trap faster than cleaner water. Ditto for the carbon block. It has been my experience that chlorine / chloramine levels in city water are higher in the summer than the winter. For  someone who makes a lot of water (like we do at the shop) this might requirer more frequent replacement of the carbon block. Bottom line is time is not what is going to determine filter life, it's how much use is done and how bad is the source water.

This is another area that buying cheep is not a good idea, spend the money to get a good unit. It will give you better quality water and possibly save a little money on your water bill by not wasting as much water.

[aquavista99]

Bottom line is time is not what is going to determine filter life, it's how much use is done and how bad is the source water.

Good point, Joel. I make about 100 gallons or so of RO/DI water per week and the water source in my area is so bad that I go through RO membranes every 6 months and change out DI resin every other week. I change the micron sediment filter and carbon blocks every four months. I use only quality membranes (Filmtech 75 gpd) and filters as well (Micron Purtrex Depth Sediment filter + MATRIKX CTO®/2 Carbon Block + MATRIKX® 1 Carbon Block).

[aquavista99]

http://www.reefkeeping.com/issues/2005-05/rhf/index.php

Very detailed article on RO/DI. Excessive carbon dioxide in the source water (well water) and not using a water softener (hard water) describes my tap water source perfectly.

[aquavista99]

I go through RO membranes every 6 months

FYI - most RO membranes should last up to two years or longer. I think I may have other issues going on that cause my membranes to fail sooner as opposed to later.

[verper]

Good point, Joel. I make about 100 gallons or so of RO/DI water per week and the water source in my area is so bad that I go through RO membranes every 6 months and change out DI resin every other week. I change the micron sediment filter and carbon blocks every four months. I use only quality membranes (Filmtech 75 gpd) and filters as well (Micron Purtrex Depth Sediment filter + MATRIKX CTO®/2 Carbon Block + MATRIKX® 1 Carbon Block).

That's gotta be expensive!      

[Riderc82]

So does anyone have a particular vendor they recommend?  I was looking at Buckeye Field Supply's Website but other than them and E-bay I don't know of anywhere else to look.  I'm just not sure what all I truly need in a system, some have flush valves, some have valves so you can access the water before it goes through the DI membrane and some don't say what they have..... All i truly would ever need is a 50 G.P.D. unit but it looks like the water systems work similar to the Mcdonalds Menu spend another $.50 and you can get a 100 G.P.D. 

[aquavista99]

That's gotta be expensive!      

Just be thankful you have a good water source. I do buy DI resin in bulk to help keep the costs down. As Randy Holmes-Farley stated in the article you posted above, the fix to my water source problem is not cheap and would be very time consuming  ..... he suggests the following:

"If there is excessive carbon dioxide in the source water (such as well water), you might consider degassing the water first to remove some of the carbon dioxide, and thereby reduce the rate of depletion of the DI resins. Note, however, that this option is not inexpensive, and typically involves repressurizing the water with a pump. "

In other words, pump large amounts of tap water into a large tub, then add a power head to blow off excessive carbon dioxide to the tub, then pump the water back through your RO/DI unit into another tub. When you make 100 gallons of RO/DI water per week, this task becomes a part-time job and would be very time consuming.

Excessive carbon dioxide in the water supply is a DI resin killer.

[aquavista99]

So does anyone have a particular vendor they recommend? 

I purchase all my RO/DI supplies from Bulk Reef Supply.  https://www.bulkreefsupply.com

The Filter Guys and Buckeye Field Supply are other popular RO/DI vendors. As for RO membranes, the best rejection rate (98%) for the price is the filmtech 75 gpd membranes. I would recommend going with a vendor who takes the time to answer all your questions with informed answers. All of the above vendors are known in the hobby for providing excellent support even after the sale.

[UDJustin]

Or you could go to your lfs and talk to them about it and have them get a set up for your needs its also nice to buy from your lfs because they can help you if  you have problems, its nice to talk to people in person and not on a phone or the internet sometimes. if you couldnt tell im plugging lfs

[MechanicalEngineer]

Ok, my turn!

I highly recommend an RO/DI unit, especially if you're planning to go SPS like you mentioned.  I used dechlorinated tap water run through a Brita filter for 6 months before bad water quality caught up to me (yeah yeah, don't laugh!) 

I want to reiterate...I would NEVER buy water from anywhere other than a place with a well-maintained RO/DI unit.  Commercial places will often use copper tubing=BAD. 

Your water company should send you a report every so often telling you how bad your water is...granted, it doesn't tell you in aquarium terms. 

I bought a well-used Coralife system off of eBay for $89+shipping (although the ad said it was barely used).  I had to replace the membrane (Dow Filmtec 75gpd), sediment filter, carbon filter, and DI resin.  I purchased the membrane from BFS (great service!) and the filters in bulk from BRS (Wow, that's confusing.  BFS is Buckeye Field Supply and BRS is Bulk Reef Supply.  LOL.) 

I make about 15-20g per week for water change water and top-off water.  For start-up costs and the cost of a new membrane and filters...I'm looking at less than 25 cents per gallon for a year of service (not including cost of water...I'm not converting cubic feet to gallons for ya...sorry.)  The convenience is worth it to me...and the knowledge that the water is pure.  After the first year of owning the RO/DI unit...the cost goes down to a couple of pennies per gallon + cost of water.

You mentioned not being allowed to plumb it.  For a while, we just hooked ours up underneath the sink...and then took it out when we needed.  It's not a permanent connection.  You might have to unplug your garbage disposal so you have an inlet for it while it runs, but that's not hard (it's a screw type connection like a coaxial cable.)  We decided to permanently stick it into the utility room, and unfortunately, the stupid house designers used plastic valves...and of course, the metal ripped up the plastic valves...and made a huge mess...and we had to call a plumber.  I think that was a worst-case scenario. 

You also mentioned what you should do with waste water.  Right before I plan to do laundry is when I make my aquarium water.  I just run the waste water line directly into the top of the washing machine...and run the water.  Even if you don't fill the washer up, it'll still help your costs.  Of course, you can always collect your waste water to water plants.  Word of caution there though...(and I'm sure Jon in SW Ohio can pitch in), I believe some plants will flower too frequency with high-phosphate water (and yes, sometimes too high of flowering frequency is bad!)  But for your common plants, it should be fine.

Hope that has helped!

Nikki

[Riderc82]

I think Hunter21 mentioned his dad wouldn't hook up a unit if he bought one.  I'm just frugal, I'm planning on doing the same thing you mentioned hook the unit up right above the washer then on Saturday when we do laundry turn the water on to the system put my five gallon containers on the floor and fill them and at the same time the waste water can be filling my washer.  The only problem I am having is trying to find a unit that allows me to turn a valve and obtain RO water (for drinking) prior to reaching the DI unit.  If I can't find a system that will allow me to do this without buying the holding container and faucet I guess I will just have to drink RO/DI water, after reading it looks like it is only bad for you if you drink a huge amount at one time so the liter or two of water I drink a day shouldn't kill me.  Maybe I'm not frugal maybe I'm just cheap does anyone else still take there aluminum cans to the scrap yard? 

[Hunter21]

correct, I said my dad wouldn't let me hook anything up and no male in these parts.....  I think I'm going to try to show my dad this discussion and see if I can convince him one more time because I honestly don't want to use the water from the store, I really just want to buy a unit. But again, not my house.....  lol