The quest for 0ppm nitrates using a pozzani filter.

[**sarahp**]

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

What’s the reasoning behind filtering the water so far in advance? How and where do you store it?

 

[seangee]

What’s the reasoning behind filtering the water so far in advance? How and where do you store it?

Just my routine. I did a water change today and use 4 x 25litre plastic jerrycans. As soon as the first one is emptied into the tank I start filtering for the next WC and stack them in the garage. I have a lid with an anti-glug tap (cheap on Amazon) and to get the water into the tank I balance the jerrycan on two planks at the top of the tank and just open the tap. Flow is slow enogh not to disturb the substrate. Takes around 5 minutes to get 25 litres in and 10-15 minutes to refill.

 

[AbbeysDad]

What’s the reasoning behind filtering the water so far in advance? How and where do you store it?

I usually start filtering the same day of, or the next day after the water change. I filter cold water, so it sits and gets to room temperature before the next water change. Bear in mind that it's a trickle filtration taking about an hour to fill a 5g bucket. If I was to filter faster, it likely would not remove all of the nitrates. So I filter the water into 5g buckets. For my 3 tanks I need about 50g per week...so that's a good 10 hours of filtering over a few days!
I use an 18g tote next to the aquarium and heat the 15g of water the night before the water change and use an Eco 396 to remove water from the tank and pump it back in from the tote.
Storing: I have 30g next to me here in the DR next to my computer hutch. Another 20g is in the basement.

 

[seangee]

I use an 18g tote next to the aquarium and heat the 15g of water the night before the water change

Yup that's another big reason. At this time of year the water comes out of the tap at around 5C and my garage isn't much warmer. I move them into the house the day before so I only have to heat from room temperature as heating is the longest part of the W/C. With the Pozzani I take about an hour to filter 100 litres and some of that happens while I am doing the W/C.

 

[**sarahp**]

Update time - the good, the bad and the ugly!!!

To be fair there isn't really anything ugly - but "the good , the bad and the mediocre" didn't really fit!

Firstly, the nitra-zorb pouch - I'm not convinced that it is doing anything at all. After I did the first water change with the Pozzani and got the tank nitrates down to 5ppm I was expecting the Nitra-zorb to do it's thing and over the course of a few days get the tank down to 0ppm. It didn't! So that's a big thumbs down from me. It maybe how I have it positioned in the filter, but I don't think so. I intend to recharge it this weekend coming and see if that makes any difference.

So, to the Pozzani. I think the major thing that I have learned is that you have to let the water filter through it VERY slowly. In the instructions it says 6l per minute, but I'm not convinced that is slow enough. Unless it's a trickle it seems to come out at 5ppm ish. Obviously that is still better than 50ppm coming out of the tap but not the zero I was shooting for.

The other issue is temperature. When I used to do water changes before I used to use the hosepipe from the outside tap (obviously very cold water) mixed with water from the kitchen tap which I had much warmer. I used to combine the flows of each and end up with water that was about 1 or 2 degrees lower than what I had taken out.

As I was using the Pozzani from the kitchen mixer tap I had the water coming through it at about 21c. It was actually much easier that trying to mess about with bottles and the hose so I quite liked that idea.

However, I'm not sure if the increased warmth of the water has affected the efficacy of the filter. When I did the second water change the other day it was coming out of the filter at 5ppm but I'm not sure if that was because I had the flow rate too fast or if I have messed up the cartridge by using warmer water. Maybe someone with more science knowledge than me could answer that?

I have now bought a new cartridge replacement, so when I do the water change this weekend I can test whether its flow or heat that is causing the lack of 0ppm.

Obviously 5ppm is not ideal, and I am still trying to get 0ppm, but it's still loads better than it was so I will take that for now.

The Quest continues.........

 

[**sarahp**]

I have a lid with an anti-glug tap (cheap on Amazon)

Do you have a link to this? I am considering following your system of pre-filtering the water. I tested room temp water in my house and it is about 19c, so only 5c off the tank temp. Might negate the warm water problems that I have been experiencing (if that is what is causing the 5ppm).

 

[seangee]

This is the cap https://www.amazon.co.uk/gp/product/B01F93N7MA/?tag= and I use 4 of these https://www.amazon.co.uk/gp/product/B003URSXQI/?tag= to store and pour. Do think about the weight though, 25l is close to the limit of what I can comfortably lift onto the top of the tank .

I tend to run mine in at about 2-3 liters per minute. Usually takes me between 10 and 15 minutes to fill the 25 litre can. Yesterday was the first time my test strips showed any pink AFTER filtering but I did run it through a little faster than usual. At a guess that's about 2 months and 2k litres

 

[AbbeysDad]

As for the Nitra-Zorb pouch, it needs to be placed in the filter last following a fine filter pad or floss as it's ability to adsorb nitrate is compromised by detritus that coats the resin pellets.

For the pouches, after a time, they become less effective or ineffective due to detritus. I am experimenting with a bleach/water bath to burn off organics (A similar procedure as is used for Seachem Purigen). The key (according to MARS/API tech support) will be to do this, rinse well AND treat with Prime to fully de-chlorinate before recharging in salt water.
Note: I'm only planning to do this to extend the life of pouches that have reached the end of their use life. There is no detritus in my DIY tap water filter and with periodic salt water recharges (at about 200g filtered) I have filtered about 2000g to date and still going strong! This suggests to me that if the organics are removed, the pouches should last a very long time!

A slow flow through these resins is a must to ensure sufficient residence time, otherwise not all nitrates will be adsorbed. As I mentioned I have a flow rate that filters 5g in about 1 hour. Temperature is not really a factor, however everything I've read indicates you should never use HOT water. But cold or room temperature water should be fine. However, since I do my filtering nearly a week before the WC and pre-heat it with a spare heater anyway, I always filter using cold water form the tap.

As to lifting to pour into the tank, consider an Eco 396 submersible pump, It works great and only costs around $20 US.

 

[seangee]

Extra change this week cos I'm off on me hols tomorrow. Here's the low tech solution in action. The first half involves a hose and buckets

 

[seangee]

Yesterday was the first time my test strips showed any pink AFTER filtering but I did run it through a little faster than usual. At a guess that's about 2 months and 2k litres

Slowed the rate right down today. That cartrige is done. I'll update in a few weeks how recharging with salt works out.

 

[AbbeysDad]

Extra change this week cos I'm off on me hols tomorrow. Here's the low tech solution in action. The first half involves a hose and buckets

A process that needs improvement! You need a pump and a hose to reach a sink, toilet, or lawn and a bin/tote to pump the fresh source water back in!

Don't be too surprised if you can't recharge the cartridge. I tried once on an inline nitrate filter cartridge and it just didn't work.

I don't know if it was a different resin or the nature of the cartridge design just didn't allow the brine solution to work.

Have a nice holiday!

 

[seangee]

Don't be too surprised if you can't recharge the cartridge. I tried once on an inline nitrate filter cartridge and it just didn't work.

Not holding my breath. It will be a bonus if it works.

 

[Wills]

Nicely improvised! I use a pond pump for mine and I luckily have a waste pipe for my washing machine within reach so I can just quickly unhook that and put the pipe from the tank in to drain away.

We want to redo our kitchen later this year/next year and I will be moving my tank - Im due a new one anyway as this one is nearly 10 years old, I want to find somewhere that can help me plumb in a really easy water change system with pipes in and out of the tank - I really fancy the novelty of having some sort of toilet flush I can pull to get the water our haha! I just think if I have this filter inline into the tank and have the chlorine filter as well it will really help if all I need to do is turn a few taps on and off.

I think with any added process like this we are all going to find our own little ways of doing it. I timed some aspects of my change last weekend and it takes my kettle 3 mins to boil and I need 3 kettles per bucket to get it to the right temperature. I havent properly timed how long it takes to empty the tank or how long each bucket takes to filter through.

Based on what you have said though, I think I will test my water after filter this week and see how I am doing. I think to get the saltwater to work you would have to get it to go through the pipe in and you would need to run it through until water came out the other side for a while, which could be tricky? A bucket and a pump might work though?

Wills

 

[SlimD]

I spoke to one of the technical guys at pozzani a while back and whilst I can’t remember all he said I’m sure he said something about the pozzani filters could be recharged with bleach if you could open them, which you can’t. The were obviously made that way to stop people recharging them and thus continue to line pozzanis pockets.

 

[AbbeysDad]

I spoke to one of the technical guys at pozzani a while back and whilst I can’t remember all he said I’m sure he said something about the pozzani filters could be recharged with bleach if you could open them, which you can’t. The were obviously made that way to stop people recharging them and thus continue to line pozzanis pockets.

I don't think so! I'm pretty sure the medium is an anion (ion-exchange) resin and if you could, you would recharge with a brine (salt water) solution, NOT chlorine bleach.