RO/DI unit upkeep

[c_scherer123]

I am going to be upgrading my 55g from freshwater to salt water.
I know that ro/di water will help prevent problems such as algae.

I am debating on whether to buy the big 5g bottles or a ro/di unit.

What kind of upkeep/maintenance (and the cost of it) do the ro/di units need?

[Quincy]

buy a ro/di unit cheaper in long run

[sitandwatch]

I just bought an ro/di unit and wish I did to start.
I only have a 34gal but have already spent almost as much on bottled water as the unit cost me.

[mike31154]

I've recently acquired a RO/DI set up and also recommend this vice buying water. As far as maintenance & upkeep, there's not that much to it and after the initial purchase, the costs are your water source, occasional filter replacements, DI resin replacement and RO membrane replacement after a few years. A lot will depend on your source water with respect to output and filter replacement etc. I'm also thinking that up in Athabasca your source water will be pretty cold most of the year. RO membranes function better with somewhat warmer water. You don't want to hook it to your hot water system by any means, but if you can find some way to warm up the input to the RO, it will work more efficiently and faster as well.

You'll need storage containers and some way to dispose of the waste water. The waste can simply be sent down the drain, but I like to keep it for the garden etc.

[sitandwatch]

I have mine hooked up to my kitchen sink so I put through warm water.

[GreenSpottedPuffer]

If your water is cold the best thing to do is use a very long supply line, coil it up and put it in a 5G bucket of water with a heater. So the supply water comes out of the plumbing cold but warms up as it goes through the bucket. I keep the heater set at about 85 degrees and it has made a huge difference in production. Less waste water too.

I forget the ideal temperature but 85 degrees is working well for me (water still wouldn't warm to 85 in the time it goes through the bucket but it warms enough) and I get 0TDS.

[TheRealBigAL]

I have mine hooked up to my kitchen sink so I put through warm water.

Ive read that you should only use cold water in your RO/DI because any warm water has been in sitting your hot water tank. Cold water is the best IMO.

[xtreme]

Ive read that you should only use cold water in your RO/DI because any warm water has been in sitting your hot water tank. Cold water is the best IMO.

I have read this as well. The input to your ro/di should be from your cold water line.

[GreenSpottedPuffer]

Ive read that you should only use cold water in your RO/DI because any warm water has been in sitting your hot water tank. Cold water is the best IMO.

Another reason to use the cold water supply and then warm that up before it gets to the RO/DI

[hillegom]

agreed, use only cold water for the ro filter. Every hot water tank has an anode of zinc in it to stop the corrosion of the glass lined steel tank. (glass lining is never 100%).
This zinc is the sacrifical anode, as in aluminum fish boats, or the lower leg of your outboard. Anyway, hot water then has zinc ions in it. Never cook with hot water, nor use hot water for the aquarium.
On a side note, if you replace the zinc anode every 5 yrs in your hot water tank, it will last a very long time.

[mark]

Feed from your cold line, but remember output rolls off with colder temps (here's a calculator (http://www.buckeyefieldsupply.com/Calculator-sp4.html)).

for maintenance, this was from Aqua-safe
When to change the filters:
PRE FILTERS: We recommend changing the Pre filters every 6 or 12 months depending on use. If your average use is approx 2-3 gallons a day then you would change them every 12 months, if your average use is approx 5-6 gallons a day then you would change them every 6 months. or Adjust accordingly for a higher average use ie. for 300 gallons a month you would need to change the filters every 3 months.

POST FILTER: The Post Carbon Final filter for taste and odor only needs to be changed ever other time from the Pre filters.

DI FILTER (Maximus and Aquarium model only): If you have a DI filter (Refillable Clear Canister with DI Resin beads) you change it when the DI completely exhausts (changes color), how long it lasts varies from system to system depending on your use and TDS. If you have the older style white disposable DI filter you change it when the water starts tasting funny or the TDS goes up.
The 6oz DI canister lasts the average family approx 3-4 months.

RO MEMBRANE: The membrane generally lasts 2-5 years. We recommend manually flushing the membrane once a month along with changing the filters every 6-12 months to prolong the life of the membrane.

[sitandwatch]

I did not know that about the hot water tank issue, I guess I will go with the cold water.

Thanks for the info

[mike31154]

Aha, one more incentive to get out there and buy that new tankless hot water heater. Shouldn't be an issue using the warm/hot supply then. Some of the better models have controller/indicators where you can dial in the temperature at various tap locations. Take advantage of the government incentives on that now too.

[c_scherer123]

Ok, a ro/di unit it is.

Are there any cons to having one with a storage tank?
I know ro water tastes terrible after a day or two of sitting - but would it matter to the fish? It is in a sealed water tank that comes with the ro/di unit.


Aha, one more incentive to get out there and buy that new tankless hot water heater. Shouldn't be an issue using the warm/hot supply then. Some of the better models have controller/indicators where you can dial in the temperature at various tap locations. Take advantage of the government incentives on that now too.
Already have one - but ours has a small 5g heated tank to use while the machine gets up to speed. So hot water isn't exactly the best in my case anyways. :)

[mike31154]

I personally don't have the type of storage tank you're referring to if it's one that comes with the system. But if so, I think they're generally meant as a drinking water add-on to the system. They have an internal bladder that keeps the tank pressurized so you can draw drinking water from a small tap which is also added on. Not sure it will hold sufficient volume for your aquarium water change needs. I think these tanks are also normally plumbed in after the RO membrane, not after the final DI stage, since that's real bland water and most people advise against using that for drinking purposes.

I guess cost of the tank is the only con really. I just have a tee with valve in the line between the RO output & DI input. Whenever I want pure water for the coffee machine or whatever, I divert from there, before the DI, and fill it into a plastic bottle.

[mike31154]

Ok, a ro/di unit it is.

Are there any cons to having one with a storage tank?
I know ro water tastes terrible after a day or two of sitting - but would it matter to the fish? It is in a sealed water tank that comes with the ro/di unit.



Already have one - but ours has a small 5g heated tank to use while the machine gets up to speed. So hot water isn't exactly the best in my case anyways. :)

Any way to bypass the 5 gal heated tank with respect to your RO/DI? The water only needs to be warm and the flow through the RO is slow enough that you shouldn't need a temp boost from the 5g heater. Generally making pure water is a long process, depending on your membrane rating. Could be a real time saver if you can run some warmer water to the RO input. Oh yes, water pressure also has a significant impact on production rates. If you're on a well or something, you might even need a booster pump. Ooops, that's more cash again...

BTW, how do you like the tankless heater? I assume it's natural gas?

[c_scherer123]

No way to bypass, and even if there was, I wouldn't because it would void the nice warranty that came with it.
I love the hot water heater - the longer it goes the hotter it gets as it gets warmed up, and the 5g water tank allows the heater the time it needs to get up to full speed. Most of them don't have the tank. It is natural gas, but it is VERY efficient (at least compared to our 35yr old one we had...). I am very glad we have it - I love it.
I am on town water, I have enough pressure that I have no need for a booster.

I am looking at this http://cgi.ebay.com/REEF-HOME-RO-DI-REVERSE-OSMOSIS-WATER-FILTER-SYSTEM_W0QQitemZ350207066246QQcmdZViewItemQQptZLH_ DefaultDomain_0?hash=item5189f7c086&_trksid=p3286.c0.m14&_trkparms=72%3A1205|66%3A2|65%3A12|39%3A1|240%3A13 18|301%3A1|293%3A1|294%3A50 unit. It has a storage tank and with the drinking faucet and a "reef" (DI) faucet so it isn't hard to bypass the di for drinking water. Bit big though, I have to check if there is enough room under my sink before I buy it. Anyone else have this one? What do you think of it?

[mike31154]

Most common systems all have the 10 inch housings for the prefilters, usually two or three, then the RO membrane and finally the DI cartridge which in the case of the system you're looking at is mounted horizontally along side the RO filter. Not sure why, but I recall reading that it is better to have the DI cartridge mounted vertically like the prefilters. Also nice to have all clear housings although that adds to the cost and the clear housings are a bit more fragile.

Here's the system I opted for from BWI in Ontario:

http://bwiplumbing.com/ca/index.php/bwi-sra-1-4-stage-ro-di-automated-coming-soon.html

Although it says out of stock and coming soon, it didn't take too long to get mine and it seems I ended up with a five stage vice the 4 stage I paid for. The three cartridges below the RO membrane contain an extra carbon element and I think one is supposed to hold the DI in the 4 stage system. In any case, my DI is in a separate clear vertical housing on it's own bracket. I just mounted both to a 2x4 so it's fairly easy to carry around. Not sure I want to mount it permanently anywhere just yet.

The price is more than the initial listing on the eBay unit you're looking at and it doesn't have the storage tank, but by the time you do the exchange rate, shipping charges and possible brokerage fees, that number will climb in a hurry and the CAN $ price of the BWI unit all of a sudden doesn't look so bad in comparison. Granted, you'll have to pay GST and shipping with BWI as well, but I don't think shipping is that much if you're not in a hurry. Finally, not sure 6 stages is required for your application, might be overkill, but up to you I guess.

[bullit67]

Ok I will admit I didnt read the whole thread but one so I dont know if any one else mentioned it but one problem you can get with bottled water is chemicals leaching from the plastic into the water I bought a bunch of water one day did my normal water change with it and noticed the next day the fish were very stressed and some corals were deal and most were not happy. When I went back to the water store I talked to the owner she knew what I was using the water for I was told that the bottles were new and the bottle manufacture did not tell them that they had to sit for a week befor they were filled as they were fresh off the line. So that was the last time I bought bottled water.

And to think we were drinking that stuff as well

[TheRealBigAL]

agreed, use only cold water for the ro filter. Every hot water tank has an anode of zinc in it to stop the corrosion of the glass lined steel tank. (glass lining is never 100%).
This zinc is the sacrifical anode, as in aluminum fish boats, or the lower leg of your outboard. Anyway, hot water then has zinc ions in it. Never cook with hot water, nor use hot water for the aquarium.
On a side note, if you replace the zinc anode every 5 yrs in your hot water tank, it will last a very long time.


100% true. well put :smile:

[TheRealBigAL]

Ok I will admit I didnt read the whole thread but one so I dont know if any one else mentioned it but one problem you can get with bottled water is chemicals leaching from the plastic into the water I bought a bunch of water one day did my normal water change with it and noticed the next day the fish were very stressed and some corals were deal and most were not happy. When I went back to the water store I talked to the owner she knew what I was using the water for I was told that the bottles were new and the bottle manufacture did not tell them that they had to sit for a week befor they were filled as they were fresh off the line. So that was the last time I bought bottled water.

And to think we were drinking that stuff as well

So then is it bad to fill up store water jugs with RO/DI and let them sit for a few days in your house ? I only use a Aquarium Pharmaceuticals Tap Water Filter so I fill 4-5 5L jugs about once a weak to make fresh water and fill my ATO. The bottles I use are originally from save-on foods. Could the plastic possibly be leaching ? I haven't seen any problems but is the possibility there ?

[bullit67]

Yah they could be but if they are well used they should be OK the bottles I had a problem with were brand new and that was where the problem was. I myself for drinking water dont trust plastics any more with all the chemicals that can leech into the water.

[TheRealBigAL]

Yah they could be but if they are well used they should be OK the bottles I had a problem with were brand new and that was where the problem was. I myself for drinking water dont trust plastics any more with all the chemicals that can leech into the water.

Good to know. thanks for the helpful tip :smile:

[Funky_Fish14]

agreed, use only cold water for the ro filter. Every hot water tank has an anode of zinc in it to stop the corrosion of the glass lined steel tank. (glass lining is never 100%).
This zinc is the sacrifical anode, as in aluminum fish boats, or the lower leg of your outboard. Anyway, hot water then has zinc ions in it. Never cook with hot water, nor use hot water for the aquarium.
On a side note, if you replace the zinc anode every 5 yrs in your hot water tank, it will last a very long time.

I've heard of magnesium being used as well because it is far down at the bottom right of the redox table too (Strong RA)... If thats the case - guess the water might be GREAT for the tanks too eh? Haha. :lol: Everyone wants good Mg+ in the water!
(Actually now that I think about it, Magnesium is even better than zinc, its lower on the table)

[mike31154]

I've heard of magnesium being used as well because it is far down at the bottom right of the redox table too (Strong RA)... If thats the case - guess the water might be GREAT for the tanks too eh? Haha. :lol: Everyone wants good Mg+ in the water!
(Actually now that I think about it, Magnesium is even better than zinc, its lower on the table)

That works until the beneficial magnesium gets to the RO membrane, whose job it is to remove any solids, including the beneficial ones... My source/tap water has fairly good calcium and not bad magnesium levels. I worked with it for quite a while, but am glad I went to RO/DI recently for my system, I can see the improvement after three water changes. Too bad there isn't a way to extract all the good stuff before the RO takes most of it out, well, there probably is, but I reckon you'd need quite a chem lab to make it happen.

[c_scherer123]

Thanks for all your help. But I hope you can help me now, I found a small stumbling block...
Most of units I am looking at are 15-18" tall and I only have 11"-12" max height to work in under my sink.
Does anyone know of any units that are about 10-11" tall and can put out 25-55gpd?

[Tomjay]

I bought the aquaticlife power unit works great...what I like about it everything is enclosed and you change the filters from the top. But it’s around 15” tall however it stands on its own base so you don’t have to mount it.

[hillegom]

Most of the units are as tall as you say. The inside filter is a standard 10 in tall.
Just measured my individual filter unit, it is 11.75" tall. If you have 12" in you could still mount the unit. Would have to mount the ro membrane, which is atop of the filter unit, separetly somewhere else, just have to plumb it in with longer hoses. And the bracket that mounts the filters, just have to turn the bracket from this: L to this: 7
A seven does not make an upside down L but you know what I mean

[mike31154]

Great ideas from hillegom. Just because the units come assembled on brackets etc, doesn't mean you can't get creative in how you wish to mount the assembly. If you get extra tubing and fittings, you can disassemble the whole works, reassemble without the brackets and stand the filters on the floor. Just need to have something for around the base of each cartridge to keep it from falling over.

The measurement of my BWI SR-1 unit, standard 10" transparent containers, is pretty close to 12" from top to bottom without the bracket though, not much room to manoeuver. You could always build a small wooden rack to mount them at a slight angle sitting on the floor, although not too far from the vertical as I don't know how that would affect performance. The RO housing is mounted horizontally anyway. Might seem like a lot of trouble, but by getting standard size cartridges, it's far easier to source replacement filters. When you buy smaller, custom and less common units, you're at the mercy of the OEM's filter format and they often crank up the price because there's no alternative when it comes to filter replacement.

[c_scherer123]

Found a better solution - use a portable unit. Bulk reef supply has some that just hook up to the faucet and I can disconnect and store it when it is not being used.
Without all this discussion I would have never found a solution - Thank you to all!

[Aleks]

Found a better solution - use a portable unit. Bulk reef supply has some that just hook up to the faucet and I can disconnect and store it when it is not being used.
Without all this discussion I would have never found a solution - Thank you to all!

That can be done with the purchase of a sink adapter on any unit.....

[sitandwatch]

I bought a full unit from Red Coral and picked up a sink adapter from revy.

I make water once a week by pulling out the ro unit from storage hook it up to the sink and tada 0 tds water.

I don't know the price difference between a portable or non portable but if its significant then get the non portable and just store it until you need it.