Sudden Nitrite (not Nitrate) in Tap Water

Linkandnavi

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Afternoon all,

Living in South East London, I've traditionally battled high nitrate levels in my tap water. Today though, I have a rather different issue.

Having just filled a 200 litre bucket ready for tomorrow's water change on my 200 gallon, I dipped a test strip in. When testing my tanks I use a liquid kit but I use test strips occasionally prior to a water change to get a ballpark figure on what the nitrates are doing. Immediately it came up with not just the usual nitrate issue, but high nitrites.

I thought that was weird, so I went and got my liquid test kit. The tap water read as follows:

PXL_20220523_150731270.jpg


That looks to me somewhere between 2 and 5ppm nitrite. The legal limit for tap water in the UK is 0.5 but usually it's just zero. This was from my garden tap as I was preparing the water change for one of the tanks in my garden office but in the UK (and I assume elsewhere?) the garden tap runs off the cold water line from the indoor tap, so should have exactly the same parameters.

A bit concerned, given my 9 month old baby uses water from the tap, I went and tested the water from the kitchen tap.

PXL_20220523_151937905.jpg


That looks like a 0.25, which is within legal limits but still higher than the usual zero. Looks like I'm going to be lugging buckets from the kitchen to my garden...

I suppose I have two questions:

1. Any idea why there would be such a massive difference between the outside tap and the indoor one, given they come directly from the same cold water line? Taken 5 minutes apart so it isn't a time thing.

2. If 0.25 is coming out of my tap indoor, there's nothing I can do about that. My Seachem Safe dechlorinator should in theory "neutralise" the nitrite for a bit, although I'm always sceptical. If it does in fact neutralise it, then it should be ok as the plants/filter should do their job before it becomes toxic again, albeit it will likely result in higher nitrates.

I posted in March that an entire tank of mine got wiped out in an afternoon, with nitrites suddenly skyrocketing without any apparent reason (here). I'm now wondering if the water I was putting in was high in nitrite and I just didn't realise. I periodically test the water being prepared for a water change and every time I have done so previously, nitrite has been zero :rolleyes:
 

Slaphppy7

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Is the garden tap outfitted with a garden hose?

If so, possible contamination of the hose could be a factor.
 
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Linkandnavi

Linkandnavi

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Is the garden tap outfitted with a garden hose?

If so, possible contamination of the hose could be a factor.
Thanks. It's connected to a hose that is permanently connected and used exclusively for my tanks.

Connects to the tap

PXL_20220523_172605688.jpg



Through my garden and through my office wall

PXL_20220523_172616422.jpg


Then to an inside hose tap

PXL_20220523_172649335.jpg


The only way to get running water in my office. The hose is food grade and never disconnected so I don't see how anything could get into it to contaminate it. At the moment though, that's the only thing that makes sense.

I just took the hose off and tested water directly from the outside tap which came up the same as the inside tap. So I'm guessing the hose must be doing it somehow.

Incredibly annoying if that's the case. It lets me fill up the bucket for water changes while I'm working so I can keep an eye on it and make sure it isn't flooding. If I have to revert to filling 25 litre Jerry cans from the kitchen tap, I'll lose an evening 🙄 particularly as I often run them through an in-line nitrate filter which basically means it trickles through
 

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Sounds like it is indeed somewhere along the hose line that is causing the issue, through your process of elimination
 

Colin_T

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Still need to let water company know there is nitrite in the water. Nitrite is carcinogenic in people, animals and birds and there should be 0ppm nitrite in the water.

I would be looking at reverse osmosis water for drinking if the water company does not get rid of the nitrites.

Garden hoses should be flushed out for 5 minutes before being used to collect water. They have softening agents in them to keep them flexible and it is toxic to all life forms.
 
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Linkandnavi

Linkandnavi

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Sounds like it is indeed somewhere along the hose line that is causing the issue, through your process of elimination

Still need to let water company know there is nitrite in the water. Nitrite is carcinogenic in people, animals and birds and there should be 0ppm nitrite in the water.

I would be looking at reverse osmosis water for drinking if the water company does not get rid of the nitrites.

Garden hoses should be flushed out for 5 minutes before being used to collect water. They have softening agents in them to keep them flexible and it is toxic to all life forms.

Thanks. I've actually now ruled out the hose and have managed to find the surprising culprit...

The hose I use is food grade and specifically free of phthalates, which is the bit that the non-food grade hoses use to keep them flexible.

Untitled.png


I've done more water tests than I can count this morning, in every configuration I could think of, and the culprit turns out to be my Pozanni nitrate filter. Which is really weird.

I've used them for a long time to try and reduce nitrate, to varying success (they work, but really don't last long) and have never had any issues with them changing water parameters. They're just an ion exchange resin. I changed out the filter cartridge yesterday before the water change but thought nothing of it as I've done that a hundred times.

But having tested everything this morning, the water running direct from the tap is running at zero nitrite, running it through the hose is zero nitrite, running it through the nitrate filter and nitrite is off the chart. I've no idea how that's possible and I intend to drop them an email now, but at least I seem to have solved the issue.
 
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Linkandnavi

Linkandnavi

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Thanks. I've actually now ruled out the hose and have managed to find the surprising culprit...

The hose I use is food grade and specifically free of phthalates, which is the bit that the non-food grade hoses use to keep them flexible.

View attachment 160044

I've done more water tests than I can count this morning, in every configuration I could think of, and the culprit turns out to be my Pozanni nitrate filter. Which is really weird.

I've used them for a long time to try and reduce nitrate, to varying success (they work, but really don't last long) and have never had any issues with them changing water parameters. They're just an ion exchange resin. I changed out the filter cartridge yesterday before the water change but thought nothing of it as I've done that a hundred times.

But having tested everything this morning, the water running direct from the tap is running at zero nitrite, running it through the hose is zero nitrite, running it through the nitrate filter and nitrite is off the chart. I've no idea how that's possible and I intend to drop them an email now, but at least I seem to have solved the issue.
For those who are interested, this gets weirder and weirder.

I swapped the problematic Pozanni nitrate filter for another one (unopened). The nitrite is zero once more, proving it was that filter cartridge. However, the new cartridge is stripping all of the carbonate hardness (kh) from the water passing through it, dropping the pH from about 7.8 down to 6. It shouldn't be doing anything to the kh and never has done previously.

I've emailed Pozanni (a) to warn them and (b) to see if they have any insight into what's gone wrong. Maybe a faulty batch of resin or something from the manufacturer - although it would be odd to cause two seperate and seemingly unrelated issues with different cartridges.

Now I have to deal with water changes with 20ppm tap nitrates until I can source replacements.
 

Essjay

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That sounds more like a water softener type filter. I know that Brita filters remove KH and drop pH off the scale - do Pozzani make something similar which may have been wrongly packaged?
 

Slaphppy7

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For those who are interested, this gets weirder and weirder.

I swapped the problematic Pozanni nitrate filter for another one (unopened). The nitrite is zero once more, proving it was that filter cartridge. However, the new cartridge is stripping all of the carbonate hardness (kh) from the water passing through it, dropping the pH from about 7.8 down to 6. It shouldn't be doing anything to the kh and never has done previously.

I've emailed Pozanni (a) to warn them and (b) to see if they have any insight into what's gone wrong. Maybe a faulty batch of resin or something from the manufacturer - although it would be odd to cause two seperate and seemingly unrelated issues with different cartridges.

Now I have to deal with water changes with 20ppm tap nitrates until I can source replacements.
Use Seachem Prime as your water conditioner, it will render the trAtes inert for 24-48 hours, and let your plants do the rest
 

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A bit of googling shows that Pozzani do make a hardness removing filter which (my italics)
uses an ion-exchange resin that removes virtually all the temporary [ie KH] and permanent [ie GH] hardness from domestic tap water.


It looks identical to the nitrate filter


This makes me wonder if they have mis-labelled your second nitrate filter.
 
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Linkandnavi

Linkandnavi

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Use Seachem Prime as your water conditioner, it will render the trAtes inert for 24-48 hours, and let your plants do the rest
Thanks. Yes, I use Seachem Safe (which the powdered version of Prime - just a bit more economical on large tanks). That was my thought too. I'm just always slightly sceptical on the whole "renders it inert" thing as I've never seen anyone really explain how that happens. That said, I have no reason not to believe it either...


A bit of googling shows that Pozzani do make a hardness removing filter which (my italics)



It looks identical to the nitrate filter


This makes me wonder if they have mis-labelled your second nitrate filter.

Yes, so those are the filter housings. I just bought the replacement cartridges.

The nitrate reduction cartridge looks like this:

1nr600.jpg


The water softener cartridge looks like this:

hm600.jpg


So almost identical, barring a slight shade difference.. I imagine that's what they've done.

They come a generic pack with the filter number attached as a sticker, so I imagine someone mislabelled.

PXL_20220524_144418954.jpg


That would explain the second filter with the loss of kh and pH but not the original issue with the first cartridge and nitrite.

They also do a fertiliser cartridge for inline flower watering systems, which could in theory add high levels of nitrite, but the resin looks completely different and I would have noticed that:

fs60p_fertilizer_cartridge_1.png
 

Slaphppy7

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I do believe you have solved your dilemma...
 

Colin_T

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What a mess. Sorry, nothing against the OP, but what a fuplie screw up making filters that look so similar but mess with the water.

Glad you figured out the problem tho :)
 

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