RO/DI unit upkeep

[mark]

Feed from your cold line, but remember output rolls off with colder temps (here's a calculator).

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.

Originally Posted by 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.

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]

Originally Posted by 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.



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-...3%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/...ming-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]

Originally Posted by 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.

100% true. well put