Is yellow RO water safe to use?

[MichaelMc]

Hi, this is my first post, so go easy on my if I've posted in the wrong forum.

Ok, so I went to my local aquarium supplier for a refill of ro water. I have only ever used this seller and I'm generally very happy with the water I get from them.

But this time, the water has a very strong yellow tint to it. The assistant assured me that this is perfectly safe, but he never elaborated on why the water was yellow to begin with. I haven't used it yet, but my head keeps telling me to dump it and get a fresh fill.

Any advice on what may be making the water this colour, or the safety of it, will be greatly appreciated.

 

[Donya]

I wouldn't use it. If it's safe then you're just out a few bucks, but if it's not you risk the whole tank's worth of animals. If you have a TDS meter you could test it and see what it reads but I can't think that water is going to give an acceptable TDS reading with a noticeable tint to it since fundamentally it means a reasonably amount of something is dissolved in it, whether it's something that made it through the RO system or something that leached in from the container it was stored in afterwards. It could just be rust in the water but even that shouldn't be in RO and probably isn't something you want to be putting in a tank that needs RO in the first place.

 

[AbbeysDad]

RO water should be clear source water forced through a membrane. I've never used RO water, but it should NOT be yellow. I wouldn't use it.

 

[Myraan]

I mean they may sell it pretinted with tannins for blackwater customers who ask for it - but if so why not just say so you know what you have.

 

[CaptainBarnicles]

I mean they may sell it pretinted with tannins for blackwater customers who ask for it - but if so why not just say so you know what you have.

Did you just make this up?

 

[Myraan]

Yes haha - I haven't heard of that actually happening... was just thinking aloud sorry

 

[Bruce Leyland-Jones]

If I'm paying for it, then I'd want to know EXACTLY what it is I'm paying for,

 

[FF_Member146894]

i saw a guy loading up well over 100 gallons of RO water into his truck at my LFS today
i don't understand why you would want to consistently waste money on store-bought water, especially when it's of doubtful quality, when you can get your own RO system pretty inexpensively

 

[Donya]

i don't understand why you would want to consistently waste money on store-bought water, especially when it's of doubtful quality, when you can get your own RO system pretty inexpensively

This is a bit of a pet peeve of mine. Saying store bought RO is a waste of money without context is kind of like saying eating out is a waste of money when you can cook food at home - there are many reasons why people might choose to pay a bit extra to get it ready made. Well water in some places can be high in mineral or salt content such that you go through RO and DI filters very fast (which makes it expensive) and renters might simply not be allowed to install/use one at all. I lived in apartment for a few years that allowed fish tanks of any size but where the taps were deliberately set up in a way that prevented sink attachments, use of outdoor garden hose by renters was prohibited, and any modification of plumbing under the sink would have been in violation of the lease. I had to buy RO or risk the lease so I bought RO. Some people also aren't physically able to set up and maintain an RO unit if they have joint/tendon/etc. problems that prevent wrenching on the canisters for traditional type units or managing the fiddly connections to replace stages on the canister-less ones. That was me for a few years too. Another reason is straight up convenience and minimizing the risk of spills. Not everyone can sit around and watch the water all day to make sure it doesn't overflow and not everyone has the space to set up a big bin with a float or optical sensor - which always still has a risk failing one day and overflowing while you're gone.

 

[FF_Member146894]

Another reason is straight up convenience and minimizing the risk of spills. Not everyone can sit around and watch the water all day to make sure it doesn't overflow and not everyone has the space to set up a big bin with a float or optical sensor - which always still has a risk failing one day and overflowing while you're gone.

a few days ago i managed to forget the RO system was filling containers and a gallon or so of water got under the floor - it warped in a few spots
i completely forget about the existence of apartments when i was writing that, i can only imagine if something like that happened in a rented place though

 

[StevenF]

The RO water is bad. Either something was added to the water to give it the color or the the filters or smoother part of the RO system has failed. You have to following choices:

1. Ask the seller why the water is yellow and what the TDS level is.
2. Find another seller of RO water.
3. Get a TDS electric sensor to monitor the RO quality. Thelower the TDS number the the higher the purity of the water.
4. get your own RO system. This system Connects to a water faucet and makes about 2 gallons an hour which can be stored in a large bucket. and waist water from the RO system is discarded down a sink drain.

 

[Colin_T]

Reverse Osmosis (r/o) water should be clear and have very little if anything in it. The whole purpose of the r/o unit is to remove impurities, including colour. If the water is yellow, it either had something added to it after it was filtered through the r/o unit, or the r/o unit is stuffed and not working properly (as mentioned by @StevenF).

The shop might have added tannins or driftwood (as mentioned by @Myraan) but most shops don't do that because people use r/o water for marine tanks and you don't want a yellow marine tank.

If the shop won't tell you why the water is yellow, find another supplier or make your own r/o water. Even if the shop does tell you why the water is yellow, I would be concerned about using it unless they have a VERY good explanation.