The quest for 0ppm nitrates using a pozzani filter.

[**sarahp**]

So when I got into the hobby, probably 12 or 13 years ago now, the things that we took notice of when setting up a tank were ammonia and nitrite - it was a given that they had to be at zero before you put fish in the tank. I did a fishless cycle because I wanted to give my fish the best possible life (I do that with all my animals!) then I looked at stocking options. All those years ago the only thing that we paid attention to in terms of whether to buy fish or not were temperament and tank size.

Things have moved on a tad since those days and now we know that nitrate is an issue for the fish that we keep in our tanks. When I started I remember being told that as long as it was less than 100ppm then I would be fine. Seemed ok to me as I was told that by a knowledgeable member on here. To be honest, I was quite relieved as the tap water where I live comes with approximately 40-50ppm nitrate, so as long as I was under 100ppm I was ok right? That's how it's been until now.

I re-joined the site, or at least started visiting more regularly, a little over a year ago and started reading that nitrates were a problem and that they too were a poison. Admittedly not as bad as ammonia or nitrite but still not great for the health of the fish. This was a bit of a worry because as I say - our water comes out of the tap at minimum 40ppm. How on earth are you supposed to deal with that??

I was in the middle of a Masters degree and to be honest I coudn't afford the time or the brain space to deal with it. I'm now getting towards the end of my course so now I can start to think about how I'm going to solve this problem. I started reading all sorts of threads and online articles about homemade nitrate removers but to be honest apart from teaching science to 7 year olds I'm not all that sciency - nor am I particularly technical in terms of making things (except chocolate cakes!) so I was beginning to feel a bit depressed. I knew my fish weren't as happy as they should be, or as happy as I want them to be but with no idea how to sort out the problem.

Then I stumbled across a thread that was started by Wills about which cichlids to get for his tank and the discussion morphed into a nitrates discussion. He put a link to a filter aimed at aquarists who have nitrate issues. To say the least I was intrigued!! I started a conversation with Wills to see what he had done and decided to do the same.

This is the filter (sorry can't seem to do a hyperlink - told you I wasn't technical!)

https://www.pozzani.co.uk/product_info.php?products_id=185

I have decided to start a bit of a diary about using this filter so that anyone else with the same issues can see how it went! I searched the internet for info about this filter from people other that the sellers but wasn't able to find much that was useful.

The filter and the hosepipe and pipe connectors all arrived over the weekend. I have spent a couple of days setting it all up so that it runs well.

I will add pictures in the next day or so but for now this is what has been going on.

All nitrate tests have been done with the Salifert test kit as I read somewhere that it is more accurate/less volatile than the API one - no idea if that is true or not but thought I'd buy that one as I needed a new test kit.

Monday 4th April

Tested the tap water 50ppm!!

Connected the hose pipe to the in and out of the pozzani filter, ran water through for 2 mins to start the filter working then tested the water coming out - 0ppm!!

Tuesday 5th April

Tested the tank water somewhere between 50ppm and 100ppm (no marker for any values in between) closer to 50 than 100.

Changed about 60-70% of the water.

Tested the water - 10ppm.

At this point I should also say that I have an API nitra-zorb pack in one of my externals. During the conversation with Wills he commented that nitrate would still be in the filters and the substrate and therefore I wouldn't eradicated it until I had done several water changes. I decided to add the nitra-zorb to try and get to zero as quickly as possible. I was also intrigued to see it as the instructions say it can be recharged. Pozzani say that their's cannot and I wanted to see the similarities and differences between the two. I'm going to trial recharging the pozzani filter as at £15 for each new canister it could get expensive.

One of the reasons for doing this diary is to keep a track of how quickly the filter needs changing and if it is a financially viable option in the long-term.

As I say I'll add pics of the set-up in the next few days. And will add to this diary as I do each water change and nitrate test.

 

[Colin_T]

I would like to know what is in the pozzani filter to remove nitrates.

Make sure you keep posting results because this is interesting.

Another option is floating plants. Duckweed and water sprite suck up nitrates as do all aquatic plants.

 

[AbbeysDad]

@Colin_T - Yes, fast growing plants (especially floating plants) go a long way to reduce tank generated nitrates, but no one can really dispute the benefits of routine partial water changes. But these can be a problem if/when there are high nitrates in the source water.
I believe that the material in the Pozzani filter is a resin that has the ability to adsorb nitrate from the water passing through it. Like API's Nitra-zorb, these resins can be recharged by soaking in a brine solution.
I use a DIY (converted [now discontinued] API Tap Water Filter filled with API Nitra-Zorb) to filter nitrates from my well water (followed by an inline carbon filter) to use for partial water changes [see photo]. Note: There are also inline nitrate filters used for ice makers, refrigerators, etc. that use the same type of resin (although these may not be easy to recharge).
In my DIY system, I get about 200 gallons before I need to recharge the resin with salt water (relative to the ppm amount of nitrates in the source water).
I do not know if the Pozzani cartridges are [easily] rechargeable.

 

[**sarahp**]

Another option is floating plants. Duckweed and water sprite suck up nitrates as do all aquatic plants.

I have heard this, and I do have lots of floating plants in the tank, but I’m not there is enough plant life space in a tank to remove nitrate at over 50ppm.

I’m not sure what’s in the filter to remove the nitrates - it doesn’t say anywhere on the filter or the packaging and I suspect that they wouldn’t tell me if I asked in case I started producing a competing product - they don’t know I’m not technically minded

@AbbeysDad - it was seeing a picture of your set-up that frightened me!! It looked very complicated and I could’t work out how to fashion all the bits together in the right places even if I could find all the parts!!

The actual filtering part of this filter does look like it contains the same stuff as the API nitra-zorb. I shall take a picture of it when I use it again so you can see what it all looks like.

Like I say, each time I do anything with this filter etc I shall catalogue it here so that people can see what is going on. If anybody has any suggestions I’m all ears!

 

[seangee]

I would like to know what is in the pozzani filter to remove nitrates.

It uses a resin for anionic exchange - exactly the same principle as the nitrazorb. I also have 50ppm tap water and started using the Pozzani around 6 weeks ago so its probably time I posted my observations. Please note these are just observations - nothing scientific whatsoever.

The reason I started my quest to reduce nitrates was that at a dinner party I discovered one of the guests kept similar species to me. Someone else asked how long fish live for and we gave quite different answers (with his being longer). We both tested both tanks and the only significant difference was my nitrate levels.

Plants: Almost all my plants are fast growing / low maintenance floating plants and I can't really say I've noticed any difference. It possibly doesn't spread as fast but I did take a bucket of frogbit out for the pond today.

Algae: This disappeared almost overnight. I never had an algae problem but used to scrape the glass twice a week. Now I do it every other week and it only needs a wipe with a sponge. Over that time I have turned my lights up from 6 to 10 hours per day as I like to keep the algae on the back wall (it has started to come back). I have zero on my driftwood, which I used to take out and scrub monthly, despite the best efforts of my bristlenose.

Fish: The tetra seem to be noticeably brighter. This could be my imagination or it could just be due to the extra light. The Corys are definitely brighter and the most noticeable change is in my 15 year old bristlenose. He was quite dull and faded, which I put down to age, but his colour has come out really well and he looks like he did 10 years ago. The Corys and Sids behaviour has not changed but there is more of it. They seem to spend less time sleeping / hiding and more time playing and foraging (or just being completely bonkers in the case of the Sids). The Bristlenose is definitely more active and always shows up at feeding time - but this could be due to less algae on the glass and wood. My Tetras also seem bigger than I have ever had them before (I can't guarantee this is the case but mine never got as big as their profiles suggest on seriously fish).

General maintenance: I used to do 2 x 60% water changes a week. For the last 2 weeks I have dropped this to 1 change. I also used to be fanatic about cleaning my substrate daily to get rid of any organic material that would otherwise end up as nitrates. A couple of weeks ago (following the advice of others in another thread) I decided to just leave it and let nature take its course - and it does. The sand is still always clean even though I ignore it. This tank has been running for about 18 months and I do have MTS so everything I needed to deal with the mulm was already in place. The tank (55G US) is quite heavily stocked (83% according to aqadvisor) and also over filtered. Between one water change and the next my nitrate rises from <5ppm to <10ppm. While I was still changing twice a week it never got anywhere near to 5.

So all in all I am very pleased with the results.

 

[**sarahp**]

One quick question for AbbeysDad - roughly how much of the nitra-zorb resin do you have in your set-up? In terms of the size 6 bags - how many are in your system? Also what is the nitrate ppm of your source water? I’m trying to work out a rough litres before it needs recharging equation.

 

[Wills]

Glad I could help Its really funny how you described your decision making process as I was exactly the same!

I'm at a point now after 6 weeks where my tank is between 20-30ppm before a water change but I need to clean my filters in the next few weeks and some of my plants are not doing so good . So I am in a much better place now than a few months ago where realistically my nitrate was reaching well over 100 in the tank.

I stocked up on the refils as I dont believe they have a shelf life just when they are used up. I didnt mind the cost too much, just a similar cost to dechlorinator.

Wills

 

[Colin_T]

perhaps the OP could do an experiment when the pozzani filter needs replacing. Put nitro zorb in the pozzani case and see if that works. If it does you could simply recharge it instead of buying new cartridges

 

[**sarahp**]

perhaps the OP could do an experiment when the pozzani filter needs replacing. Put nitro zorb in the pozzani case and see if that works. If it does you could simply recharge it instead of buying new cartridges

I’m going to try and recharge the pozzani cartridge following the instructions on the nitra zorb packet. I’ll post a pic of the cartridge and you can see what I mean.

@Wills - to be honest the cost is not my major concern, as you say equivalent to a decent dechlorinator.

Thanks for the info to get me started on this - my fish all thank you too

 

[seangee]

I do not know if the Pozzani cartridges are [easily] rechargeable.

Like Wills I stocked up on refills. After 6 weeks my water is still coming out at 0ppm but I will have a go at recharging once it starts getting depleted. I'm planning to just put the brine solution in the canister and then flushing it through (possibly reversing the flow through the filter).

 

[AbbeysDad]

@AbbeysDad - it was seeing a picture of your set-up that frightened me!! It looked very complicated and I could’t work out how to fashion all the bits together in the right places even if I could find all the parts!!

There's a faucet adapter with a tube leading to the bottom of the filter. water passes UP through the filter (containing the Nitra-Zorb) and out the top through a tube leading to an inline activated carbon filter. Then a tube leading to a 5g bucket. Pretty simple...but I had the advantage of the Tap Water Filter hardware....I just reused it to focus on nitrate removal.

One quick question for AbbeysDad - roughly how much of the nitra-zorb resin do you have in your set-up? In terms of the size 6 bags - how many are in your system? Also what is the nitrate ppm of your source water? I’m trying to work out a rough litres before it needs recharging equation.

It's been like 2 years ago now, but as memory serves me, there were about 6-8 #6 Nitra-Zorb pouches needed to fill the filter chamber. (Note: I believe that there are other similar resins on the market.) (I contacted MARS (API) and they only sell Nitra-Zorb in the pouches intended for use in filters).
At one point the nitrates in my well water were very high at 60-80ppm. Lately I believe it's more like 20-40ppm,
Since it's a completely different filter with an unknown resin, you're going to have to spot check and test for nitrates in your filtered water as you go forward since your 'mileage' will vary.

Note: I leave my filter full of water between uses - I'm not sure, but I think letting it dry out would be bad. Also, as soon as I detect nitrates in the filtered water and recharge with salt water, I let it soak in the brine solution until the next use...then I flush well with fresh water before collecting again. Also, in my process, to recharge I mix a strong salt water solution. I drain fresh water from the unit and fill with salt water. I let this set for several hours or over night, then drain and refill with fresh salt water. Then it sets, full of salt water until the next use - about a week or so.
(prolly more than the average reader cares!)

 

[seangee]

@AbbeysDad - I spotted you (or someone else claiming to be Abbey's Dad ) on another forum discussing the merits (or otherwise) of Seachem Matrix in establishing an anaerobic colony in the filter. Did anything come of this?

 

[AbbeysDad]

@AbbeysDad - I spotted you (or someone else claiming to be Abbey's Dad ) on another forum discussing the merits (or otherwise) of Seachem Matrix in establishing an anaerobic colony in the filter. Did anything come of this?

As mentioned recently in another thread here, I tried for 3+ years to culture anaerobic bacteria in my 60g FW tank without success. At first I added an additional Aquaclear 70 filter with an AC20 impeller (for slower flow) filled with a mix of Matrix and DeNitrate. Thinking of it as a dedicated bio-filter with the capability for anaerobic bacteria. I repeatedly seeded with Seachem Stability. Later on I tried a 4 Liter Loc & Loc canister with a Tom Aqua Lifter pump (3.5gph) filled with a Matrix/DeNitrate mix. Again seeded with ample amounts of Stability and later on Aquabella. At no time did I see any measurable reduction in tank nitrates. We know that culturing anaerobic bacteria in SW is done with live rock, deep sand, and/or algae scrubbers, and countless types of reactors, but I just couldn't get it to happen in my FW tank. Is it possible???....perhaps, but I just couldn't make it happen.

I resigned that the best (and perhaps easiest) way to naturally lower tank nitrates (in addition to proper feeding with high quality foods, good tank/filter housekeeping, and routine partial water changes with nitrate free water) is with fast growing (especially floating) plants to convert ammonia/nitrates into plant mass that we later remove in trimmings...and at the same time, these fast growing plants remove other pollutants (aka nutrients) from the water column.
(Even with routine weekly 50%+ water changes, tank water pollution is on a bell shaped curve. Fast growing plants help flatten this curve to a better level, producing a more consistent level of water purity over time.)

Footnote: When you have to pre-filter water for water changes, you become motivated to reduce tank nitrates/pollution as much as possible to maximize WC effectiveness.

 

[seangee]

When you have to pre-filter water for water changes, you become motivated to reduce tank nitrates/pollution as much as possible to maximize WC effectiveness.

I know that feeling - I have just filtered 100 litres for next week's WC

Was curious because I suspect that in a mature tank with plants there isn't actually that much (bacterial) activity going on inside the filters. As I am about to start a new tank it would have been the opportunity to move some of my current media into the new filter and replace with Matrix, but considering the price and the fact that nothing is broke I don't think I'll bother.

 

[AbbeysDad]

...
Was curious because I suspect that in a mature tank with plants there isn't actually that much (bacterial) activity going on inside the filters. As I am about to start a new tank it would have been the opportunity to move some of my current media into the new filter and replace with Matrix, but considering the price and the fact that nothing is broke I don't think I'll bother.

With my experiences with Matrix/DeNitrate I came to realize that sponge material in the filter was not only a great mechanical filter, but also a great beneficial bacteria platform - so all I have in my AC70's filters now is sponge material (And many large fishrooms run on only sponge filters).
I think that even in an established planted tank there's always BB in the filter(s). After all, it's a great place as food and O2 is constantly delivered!
On a couple of separate occasions I have taken the sponges from my established planted tank and cleaned/rinsed them in new tank water to 'instant cycle' the new filters - works without fail!