TDS and old RO storage containers

[reeferjw]

I have been battling cyano for while now. I am now wondering if the 5 gallon common water containers from the LFS could leach something into the water once they get older. I have 3 of them that I bought used when I had an emergency with my first tank and had to break it down. I used those to fill up my new 28 G nanocube. I have been using these to store purchased RO. I got lazy and quit using my RO/DI filter because I didn't have a permanent set up. I am going to get it going but, if the storage containers are bad, it won't make any difference.

I just tested TDS in one of them and it showed 32ppm. Now I am wondering if that is contributing to my cyano issue, since I am doing weekly 5G water changes, running GFO in a Phosban reactor, along with carbon, and an Aqua C Remora protein skimmer. I even cut a piece of a phosphate absorbing pad to put in the middle chamber with filter floss.

I know that it is possible the RO from the LFS could be an issue, but I'm not jumping to that conclusion. Besides, I am going back to my own RO/DI system. I had heard that some BRUTE cans had leached stuff in the past, but being that these are intended for use in the aquarium trade they should be good. Maybe it's just that they have gone past their useful life.

What are you using to store RO? Do you test for TDS after it sits a while?

 

[jennm]

It could be a number of things. RO/DI water is pretty aggressive but I've not heard of food grade containers, 'going bad'.

Do you clean the containers at all? Do you only use the containers for clean water (don't laugh... I have seen folks use the same containers to drain waste water during a water change, then refill with clean RO or NSW....).

Jenn

 

[reeferjw]

Well, I haven only used them for RO for quite some time now, but when I got them, they were full of saltwater as I was in emergency mode, getting everything out of a leaking tank and into a temporary rubbermaid bin. You make a good point though.

I am getting my RO/DI system set up again, so I won't be needing them to store RO.

 

[schwaggs]

Its really tricky to measure TDS. Just the tiniest bit salt, dirt or dust can impact the reading.

I wouldn't think the container would leach nutrients for the Cyno, especially if they have been holding only RODI water all along. Did you try getting your water from another store to see if that makes a difference?

 

[porpoiseaquatics]

My comment is this....RO/DI water should be 0 TDS. My water from the faucet is around 31 ppm so if your water in the bottle is measuring that and you said you got it from the store....there is a problem...it's not RO/DI water at all!

 

[lazlodawg]

I used to buy my water from a store in our area, but changed stores because I couldn't get my nitrates to drop with water changes. I tested their water and it measured 30+ppm nitrates. Tested it with a different kit and got the same results. When I asked them about it, they said I "shouldn't try to chase my nitrates". I don't go there anymore, obviously.

 

[jennm]

:boo::wow2::eek2:

Wow.

RO water shouldn't have any nitrate, even if there's some TDS from flotsam in the container. Exception being if the container is dirty from water change water per my comments previous.

TDS is total dissolved solids - could be anything but a few parts per million of matter shouldn't result in any nitrate reading.

Did you rule out a faulty/expired test kit? If it was an API test... it will test positive on nothing if it's expired.

Jenn