Storing RO water

[MarkW19]

I went to my LFS today, and the guy there told me not to store RO for more than a week max, if its not aerated, or it'll go off. I asked this question on here before I got my tank, and the general opinion was it can be kept in a tightly sealed container for up to about 6 weeks, as long as its mixed for 24 hours before use.

Who is right?

I've been storing it for 6 weeks for 4 months, and the only problem I have is high nitrates and algae. The TDS doesnt increase over time, but I tested some RO the other day and it was 2ppm nitrates. The guy says this could have come from the container it was stored in.

Can anyone help?

 

[Ziggy953]

I take it that you are buying your water? I personally don't store RO/DI for more then a few days. I fill the container that I'm going to mix my SW in for PWCs I add the salt and let it mix for a day or two and then I use it. My auto top-off is feed directly from my RO/DI unit into the tank.

What are you storing the water in? Where are you getting it? If you are buying it from an LFS I would test the water before I left the store with it. Chances are you are getting the nitrates from them.

 

[melosu58]

I make mine the day before I use it. I dont like letting it set. I imagine though it would be OK for about a week.

 

[roka64]

I leave a constant supply of premixed RO/DI SW 24x7 with a ph and heater. I agree about a week would be ok, just make sure it smells ok. Still water can stagnate.

 

[MarkW19]

I buy my RO from my LFS. I had my own RO unit when I had a tank a couple of years ago, but that was one thing that put me off TBH. Having it running all night in the bath etc., I told myself this time I'd just go to the LFS and buy it ready done.

BUT, my LFS isn't nextdoor, so going every week (or even two) isn't feasible. I was told up to 6 weeks would be ok, as long as it's aerated 24 hours before use, but it looks like most are saying that's too long? It always smells absolutely fine, I stick my nose in the container each and every time I take some out to mix, and it smells fine.

I did check the nitrates of the new RO today at the LFS, and they were 0. So I guess I'll test them in a couple of weeks to see if anything's changed.

The guy did tell me something very odd though, that he's had his reef for 5 years and just uses (soft) water straight out of his tap, not even conditioned/dechlorinated! Not RO, just tapwater! Says he's never had any problems, not even any algae. He also believes that LR is 90% of peoples' algae problems. Strange...

 

[usmcmarc]

I keep mine about a week in a 5 gallon jug, it works fine. I pour it in my mixing bucket add salt, let it set overnight w/ PH and heater.

 

[fijiwigi]

I guess I never really thought of that I have 25 gallons prepped up sitting in a garbage can and I only will change about 10-15 gallons a week. What is the difference between leaving it in a garbage can or pre-bottled water or Store bought ocean water. I didn't think water could expire. If so how does it maintain during the trip from the water plant to my house... The RO/DI unit only removes impurities I wouldn't think it would give the water an expiration date. If the water is in your tank it doesn't expire after a week it is still in a container just circulated. I would think that if there is a decent powerhead flowing the water around that It could stay there as long as you want before use, If not I would definately need the scientific explanation beyond the theory....................??

 

[melosu58]

If so how does it maintain during the trip from the water plant to my house...

The trip to your house from the water plant is a very quick trip. A few days at the most. I work for a water plant and I know mine adds caustic soda which has a very high PH because when the water gets to you the PH is so low that it needs the higher ph to bring it up to where it needs to be. Traveling through that pipe with no oxygen causes a very low PH. You really cant compare a water line to a RO/DI unit. One takes impurities out while the other adds chems to it to keep it safe for you. It`s apples and oranges. JME

 

[cmor1701d]

RODI water stored in a closed container is not going to go 'off'. Back in the day (60's) Civil Defense stored water in bomb shelters for years. It did not go bad.

I fill a 45 gallon BRUTE (food grade) bucket once a month or so wiht RODI for my top off water. It's rather tightly sealed and the water at the end is just as good as the water that went in.

 

[fijiwigi]

The point of comparing the house water to the RO/DI water was really just that it doesn't expire. I know they are different quality for sure. I see that cmor1701d stores his for a month before use which is what I do as well I guess. My question though would be how long would Saltwater be good for after it is mixed with a powerhead and a heater in the Garbage can. I personally don't understand why it would not be good for years. There is nothing to absorb any of the elements in the salt it is just sitting there Just like those Real Ocean water bags you can buy at the Pet Store. Does anyone Disagree with this if so Why???

 

[ellisz]

I have never had issues storing water. I go through 3-5 gals a day though so it does not last long

 

[Charlie]

I store RO/DI water in 5 gal water bottles with snap tight lids. I usually keep them for a few weeks before bringing them to the office where the salt is added. I airate for a couple of days and then dump into the fuge. Haven't had any problems yet.