Nitrates in my rodi water

[GraffitiSpotCorals]

Help me out guys...

 

So suddenly I have been having issues with nitrates creaping up. I haven't changed anything on my rodi unit which has been working for years. All filters were good and I even changed out the prefilters. Still getting about 4ppm nitrates per salifert kit. I am wondering if somehow I am getting chloramines which hampered my ro filter but it's new too and still getting 3tds after the ro unit. Other than that I have no clue why I would be getting any reading at all. Anyone have any ideas? It's defiantly coming straight out of my rodi unit. I am also afraid phosphates are coming out too but don't have a test kit for it on me. I will have to check everything again tomorrow since I changed all prefilters. I did check right after I changed them though.

 

I have seen a color shift on a few acropora which worried me so I checked things and found my rodi top off tank had white bubble bacteria growth at the top of the water. This is when I checked my source water. I had two acros rtn in the matter of hours which looked like a bacteria infecting just ripped through them. Others look ok for now. This could have happened because I upped my carbon source some to drop the nitrates back down, which reached the same as what was coming out of my ro unit, 4ppm. That took care of the nitrates and phosphates in the tank but could have caused the rtn. Or more than nitrates are getting through. I am getting 3ppm after ro and 0 after di like always though...

 

Anyone in Prince william county getting bad rodi water?

[John Ford]

PW county uses chloramines in the winter to flush their systems out. I'm not sure when I just know at some point.

 

I have noticed some cyano in my tank but was blaming it on slowly changing out my sand bed and stirring things up. I have also never tested for nitrates so I can't help you there..

[Origami]

Is your DI resin exhausted? Nitrate should not be able to get past your anion resin. If you're anion resin is depleted, it could be releasing (negatively charged ions like) nitrates and phosphates back into your RO/DI water.

[GraffitiSpotCorals]

New di resin

[Origami]

And you're sampling directly to a clean container and not from a reservoir of some sort? Also, let the RO/DI run for a little bit to give time to flush, then take your sample.

 

Try running your test kit against a distilled water sample from the drug store to make sure it's not the culprit. 

[GraffitiSpotCorals]

Yea I am going to double check everything when I get home and will post results.

[GraffitiSpotCorals]

I got a zero reading after running the water for a few min and testing off it. I knew you get less effectiveness of your filters off running your ro line straight to your top off tank but I didn't k lw you could get nitrates building up... Doesn't make sense. I am going to run a line off one of my storage tanks to gravity feed my top off so I can fun the ro filter once a week for a larger amount of gallons and see if nitrates show.

[Origami]

Paul, how long is the plastic line running between your DI stage and your reservoir been in place? Could it be that there's a bacterial film in there that is causing the nitrates to build up in the water left standing in the line in between production cycles? Maybe you want to change that line out?

[zygote2k]

Could check with another test kit first....

[GraffitiSpotCorals]

I double checked with new test kits, I am getting correct readings with both.

 

I actually just bought extra line to replace it, I didn't think about it having stuff accumulated in it but that's very possible for all the times I have left the valve opened.

[SandJ]

Silly question, I am assuming you are testing your RODI water....are you using a saltwater or freshwater test kit on the RODI to test for nitrates?

[epleeds]

Paul

 

Have you changed out the line yet? I have been fighting STN for about 3 months now. Not everything is effected. Just my nicer stuff :(

 

I am about to pull both my water barrels and power wash them both. I have replaced almost everything else.

[GraffitiSpotCorals]

Salifert test kits two new ones to double check. They say fresh and saltwater.

 

Eric I am going to wash my storage barrels as well. Send me a text and we can share notes and maybe find what's up.

[GraffitiSpotCorals]

I think my stn was not related and nutrients played the role in the color shift I saw. But I still know I need to fix the situation or things will not progress.

[Origami]

Salifert test kits two new ones to double check. They say fresh and saltwater.

 

Eric I am going to wash my storage barrels as well. Send me a text and we can share notes and maybe find what's up.

 

Good idea. Storage barrels also develop bacterial films over time. You may want to wash them at least annually. For salt water storage, if there's any calcium carbonate build up, I'll use acid to dissolve the deposits and then give it a good rinse. After that, I'll use a scrubbie and baking soda on the interior surfaces. For freshwater storage, use a scrubbie with some vinegar and rinse. Follow up with a scrubbie and some baking soda. The intent of going acid to base is to pH shock anything that might be living on the surface.

[GraffitiSpotCorals]

Exactly what I had planned. I have everything out and about to start. I will share the results once I have ran water for a while. I appreciate the help man. Your a huge help to a lot of people here. I don't want to let that go unnoticed.