Purigen Alternative

[Ria95]

Hi all,

That is the <"Aquarium Science"> review.

I'm <"not qualified to pass comment">, although I'm going to imagine that it maybe <"pretty near the truth">. It would be fair to say he isn't exactly a Seachem fanboy.

From <"5.5.3.2.1. Prime, Safe and Ammonia">

cheers Darrel

I think it’s clear by now that I am no Seachem fan myself, but making exaggerated negative claims, as in that article, also does not help the hobby. It’s not a source I would reference much. The author there seems to have a beef that it is described as "an "organic scavenging resin":

It categorically is not an “organic scavenging resin”. The hydrophilic carboxylated acrylate chemistry is used in making baby diapers. This would appear to simply be one of the plastic resin bead feed stocks for making baby diapers.

Is it a resin? The author of the same article says two sentences after it’s simply a plastic resin bead. A quick search for acrylate resins will give plenty of places that call polycarboxylates resins. So even if we take the author’s guess at the composition of purigen, it’s a resin.
Is it organic scavenging? Just a few paragraphs up the author sets up tests where chlorophyll, red food coloring, methylene blue, safranin, tannic acid etc are reportedly completely removed by Purigen. Those are all organic substances. They have a very discernible color to them so can be easily seen when they were taken up by Purigen. Yet it is suggested that it doesn‘t remove organics... perhaps Purigen has a fancy for brightly colored organics.

Just using the information given by the author the ’categorically is not‘ argument is dismissed.

The experiment with nitrogenous waste removal is also rather shoddy.

4 ppm of nitrogen was added in the form of food every day.

So 4 ppm N every day, then he tests water for nitrate after 2, 4, 8,16 weeks. How is it that after 2 weeks he detects 40 ppm NO3 in all tanks ? 4ppm N * 14 days = 56 ppm N ( 248 ppm NO3). After 16 weeks, 400 ppm NO3 are reported .... yep that‘s not as expected 4 ppm N *112 day = 448 ppm N ( 1983 ppm NO3). Even if we generously allow 10-20% loss to assimilation, it‘s way off. I wonder how he dealt with HCO3 loss from all that nitrification...seems a secret.
Besides can you imagine how a tank with 448 N from organics for 112 days looks like? I say imagine because I cannot find any image of the setups and tests, just random fish.etc. etc.

Yes microorganisms will colonize the filter media and I don‘t expect the organics in there to be eternally stable. That’s why it’s good to clean and replace / renew them if we truly want nutrient export. There are some alternatives , like Masterline - Purity coming to market but can‘t say they are cheaper... maybe a trial with baby diapers aquariumscience.org-style (please don’t)

 

[dw1305]

Hi all,

but making exaggerated negative claims, as in that article, also does not help the hobby.

I think he might have lost a little bit of objectivity.

Just a few paragraphs up the author sets up tests where chlorophyll, red food coloring, methylene blue, safranin, tannic acid etc are reportedly completely removed by Purigen. Those are all organic substances. They have a very discernible color to them so can be easily seen when they were taken up by Purigen. Yet it is suggested that it doesn‘t remove organics... perhaps Purigen has a fancy for brightly colored organics.

Yes, you can't have it both ways, that was partially why I put the link into <"Seachem Help desk comment"> from @Craig Matthews <"Pink tinge"> thread.

So 4 ppm N every day, then he tests water for nitrate after 2, 4, 8,16 weeks. How is it that after 2 weeks he detects 40 ppm NO3 in all tanks ? 4ppm N * 14 days = 56 ppm N ( 248 ppm NO3). After 16 weeks, 400 ppm NO3 are reported .... yep that‘s not as expected 4 ppm N *112 day = 448 ppm N ( 1983 ppm NO3). Even if we generously allow 10-20% loss to assimilation, it‘s way off. I wonder how he dealt with HCO3 loss from all that nitrification...seems a secret.
Besides can you imagine how a tank with 448 N from organics for 112 days looks like? I say imagine because I cannot find any image of the setups and tests, just random fish.etc. etc

I'm not convinced by that as well, and the 40 and 400 ppm NO3 also look a bit suspicious, I', gong to guess they are due to the dilution of the sample. I'm generally dubious of all NO3- readings, even ones I've done myself with an Ion Selective Electrode.

cheers Darrel

 

[Ria95]

Nice, thanks for the screenshot. I suspected that to be the case but it’s nice to have confirmation from the manufacturer.

 

[erwin123]

Purigen doesn't seem to have an effect on water stained pink/red by Fe-EDDHA. Is the reason for no effect because the tinge comes from inorganic rather than organic molecules (or ions) ?

 

[_Maq_]

Is the reason for no effect because the tinge comes from inorganic rather than organic molecules (or ions) ?

No. EDDHA is an organic acid. The tinge always comes from the metallic ion bound within, i.e. trivalent iron.
It's interesting to note, however, that Purigen does not remove it.

 

[Aqua sobriquet]

Rookie Error!

I failed to rinse the bag of Purigen thoroughly and when I turned the filter back on I got a cloud of dust spewed into the tank!
I won’t be doing that again with the second bag.
I decided on a large water change to help rectify the problem whilst the Biomaster did its thing.
The following morning the tank looked crystal clear. In fact I’ve not seen the water ever looking so good.
It’s a shame Purigen is so expensive and that you can only regenerate it four or five times.
I’m wondering if there’s any mileage in regenerating it before it gets too bad rather than leaving it longer?
I’m impressed with the bag it came in, it’s a type of hard plastic mesh rather than the more usual soft stuff.

 

[Hanuman]

It’s a shame Purigen is so expensive and that you can only regenerate it four or five times.

Not sure where you got that from but I have regenerated mine well over 10 or 15 times and still it's working, so all in all it's probably cheaper than using carbon.
Only problem I had though is that one of the bags slightly ruptured one time and the next morning I found snow all over the tank. Luckily it was nothing major as only a very small portion had escaped. I melted the plastic with a lighter and all was back on track.

 

[Aqua sobriquet]

Not sure where I read it. When the time comes then I’ll continue to attempt to regenerate it. Can I assume that if it looks similar to its original appearance it’s still likely to perform ok?

 

[Hanuman]

Not sure where I read it. When the time comes then I’ll continue to attempt to regenerate it. Can I assume that if it looks similar to its original appearance it’s still likely to perform ok?

I guess so. Nothing is eternal though but as long as you see that the beads turn dark/brown I guess they are doing something.

 

[_Maq_]

Can I assume that if it looks similar to its original appearance it’s still likely to perform ok?

Again, there's a big question of Seachem's honesty here. How many times can it regenerate? And does bleach / Seachem Prime procedure preserve it's quality better than hydrogen peroxide?
After multiple uses, my Purigen has got brown and H2O2 could not remove the colour. I was probably correct in assessing it was trivalent iron, and I succeeded in removing it with a reducing agent - oxalic acid. Purigen turned back very clean, almost white, slightly yellowish. Is it like new, fully effective now? How can I tell? It seems it works well. In any case, I've not observed any harmful effect. If browning is a sign of efficiency, then yes, it's getting brown in the tank (I don't have filter) just like the first time. So I guess, it still works.

Still, I prefer activated carbon. But I have to add without delay that very much depends on what AC you use. I've found my source, I acid wash it myself, and a sack of AC is hanging in my tanks permanently. It's effect is subtle, and it cannot replace water changes. Yet in my experience, the benefits are clear: clearer water, lower incidence of unwanted events.

 

[dw1305]

Hi all,

Purigen doesn't seem to have an effect on water stained pink/red by Fe-EDDHA. Is the reason for no effect because the tinge comes from inorganic rather than organic molecules (or ions) ?

That is interesting, we have another thread where the <"Purigen went pink">.

cheers Darrel

 

[MichaelJ]

Not sure where you got that from but I have regenerated mine well over 10 or 15 times and still it's working, so all in all it's probably cheaper than using carbon.

I must say in my case they get really hard to clean after 5-6 times. Keep in mind when I remove mine for cleaning after a month or so they are extremely dark brown, almost black... I only use Purigen when I have too much tannins. I do not rely on it for anything else, and for that it works fine for me.

It’s a shame Purigen is so expensive and that you can only regenerate it four or five times.
I’m wondering if there’s any mileage in regenerating it before it gets too bad rather than leaving it longer?

Yes. I think I possibly could get more mileage out the bags if I would remove and clean them before they get extremely dirty, say every two weeks instead of a month or so.

Cheers,
Michael

 

[Aqua sobriquet]

It’s a shame about the bogwood in my tank. It’s been in there a few years and still leaking tannins. It looks good though with moss growing on it and the shrimps seem to like it. I don’t think I’ll be risking bogwood in my next tank though.

 

[PARAGUAY]

I think the thing about all these products is simply expectations, you can't expect it(Purigen) to work as well in say a large fish large tank scenario. Green Aqua call it their"secret" to crystal clear water. Their showroom
aquariums needs to look good all year round. But it not a replacement for good husbandry with a aquarium. I have a couple of bags over two years and can still regenerate "creamy white"
Compared to activated carbon £8 a bag?(in the UK) needs replacing after 6 to 8 weeks, last time l looked small bag Purigen around £12 and lasts l would guess at least 12months in a well kept planted aquarium seems good value to me, but it not essential for a nice aquarium although contest competitors aquarium chaps would mostly disagree

 

[MichaelJ]

Compared to activated carbon £8 a bag?(in the UK) needs replacing after 6 to 8 weeks, last time l looked small bag Purigen around £12 and lasts l would guess at least 12months in a well kept planted aquarium seems good value to me, but it not essential for a nice aquarium although contest competitors aquarium chaps would mostly disagree

Very much agree. For me it’s purely an aesthetic thing - definitely not essential. I actually don’t even think Purigen is offering any other significant filtration benefits other than polishing off those tiny “impurities” such as the tannins.

Cheers,
Michael

 

[_Maq_]

Compared to activated carbon £8 a bag?(in the UK) needs replacing after 6 to 8 weeks

I dose 1 g AC per 1 liter and, according to my observations, it works 3 to 4 weeks in "clean" tank. In a troubled tank, the dose or/and longevity would be bigger, and shorter respectively.
AC normally sold in hobbyists stores is (a) often unsuitable, made of coconut, (b) awfully overpriced.
I've chosen my product, AC made from coal (made in Poland), and purchased 25 kg bag for roughly 100-120 pounds. Enough for me and my children, I guess. For a 100 liter tank, one dose makes 0.48 pound.
I wash it in acid because most of my tanks are softwater and minerals leaching from AC could influence my carefully created and observed chemistry.

Why bother? That depends. Organic pollution is my obsession, and I maintain it's the greatest source of troubles. Water changes are necessary, but with AC the results are still a bit better. You can either agree, or disagree and take AC for useless, too expensive, or so.

 

[Aqua sobriquet]

It’s just an aesthetic thing for me. The best carbon I found was the Fluval stuff but it only lasted 3-4 weeks before the colour came back.
The tank at the moment with the Purigen in it has never looked so clear.

 

[Aqua sobriquet]

I use Ziss ZMll media in my Biomaster which always ends up floating about when I clean the filter. So I decided today was the day to cut a filter screen for the tray. Whilst I was doing that I decided to try cleaning the Purigen. It’s only been in the filter about two weeks so not that dirty yet. I put it in a tray of 12% H2O2 and let it sit for about half an hour. I then gave it a flush with some hot water and this is the result. I’m not sure how well it will work when it gets really dirty after a few months though. I may need to try the bleach method?

 

[Hanuman]

I may need to try the bleach method?

View attachment 203207

It's not fully regenerated as is. It should look very close to when you got it new.
IMO 12% H2O2 is too high of a concentration. I would use 6% but that's just me.
You could try bleach to finish it up but you will need to neutralise the bleach afterwards.

 

[_Maq_]

I'm using more diluted hydrogen peroxide, and leave it in action for several days.
That what you show as a result is clearly unsatisfactory. More time needed.