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Use of Activated Carbon, Purigen, etc.

dw1305

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Hi all,
I have my doubt that Seachem produces the product called Purigen themselves... They most likely have a contract with the producer to sell under a so-called different brand/trade name.
This is what <"Aquarium Science"> says, I'm not a chemist so I can't vouch for the veracity of it:
...... As a chemist well versed in polymer chemistry, based on the fact that the material swells in water and based on the decomposition products listed in the MSDS (no nitrogen compounds and no sulfur compounds), Purigen is simply a hydrophilic carboxylated acrylate polymer structure which gives a “macro-porous” surface for beneficial bacteria to colonize. ...........

There are no special properties which such a plastic would have. 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.......
I don't know if that would contradict? Its ability to <"filter out tannic substances and dyes">.

cheers Darrel
 
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Hi all,

This is what <"Aquarium Science"> says, I'm not a chemist so I can't vouch for the veracity of it:

I don't know if that would contradict? Its ability to <"filter out tannic substances and dyes">.

cheers Darrel
Thanks for that Darrel. It seems Purigen is no better than carbon for removing tannins that colour the water?
I gave up on the idea of using it not only because of the cost but also pouring bleach down the drain after recharging it.
It seemed to me rather daft to use it in a fish tank then pouring products down the drain that can harm wild fish.

If an alternative product is available at a reasonable cost that doesn’t require bleach then I’d be interested.
As a matter of interest I buy 12% H2O2 anyway if that can be used?
 

dw1305

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Hi all,
It seems Purigen is no better than carbon for removing tannins that colour the water?
It might depend on the grade of activated carbon you use.
when we can do a big weekly water change what is the point of activated carbon? I am not being critical, just don‘t get it
I actually <"go out of my way"> to make sure the water always <"has some tint">.

I think if you keep <"Lake Tanganyika surge zone Cichlids"> then you might want clear water, but for everything else I'm pretty sure that some humic substances <"are an unalloyed good thing">.

cheers Darrel
 
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_Maq_

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This is what <"Aquarium Science"> says, I'm not a chemist so I can't vouch for the veracity of it:
I wonder who stands behind 'Aquarium Science'. I know something about home experiments. They are rather costly, and above all, time consuming. I wonder who could possibly perform so many tests as an amateur? True, the author does not insist to be an amateur. If he/she is a pro, then crucial question arises: who pays for that?
It routinely attacks all commercial products. In that, I may agree in many instances, but again - doing tests which prove anything is difficult, expensive, and usually takes much more time than one can imagine. In short, I'm pretty suspicious about this 'Aquarium Science'.
 

_Maq_

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Out of curiosity, when we can do a big weekly water change what is the point of activated carbon? I am not being critical, just don‘t get it.
Dissolved organics tend to get adsorbed on phase interfaces, i.e. on surfaces. These adsorbed organics create so called conditioning film. This film is a precondition to attaching bacteria, and these bacteria then create biofilm, together with other microbes. Biofilms are in turn a precondition for attached algae to "root" (in fact, algae have no roots).
If you change water, you remove dissolved organics which are at that very moment in the water column. If you use activated carbon, you reduce dissolved organics continuously (because many of them adsorb on activated carbon with its huge surface area and adsorption capacity).
 
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I wonder who stands behind 'Aquarium Science'. I know something about home experiments. They are rather costly, and above all, time consuming. I wonder who could possibly perform so many tests as an amateur? True, the author does not insist to be an amateur. If he/she is a pro, then crucial question arises: who pays for that?
It routinely attacks all commercial products. In that, I may agree in many instances, but again - doing tests which prove anything is difficult, expensive, and usually takes much more time than one can imagine. In short, I'm pretty suspicious about this 'Aquarium Science'.
It’s good to be sceptical. Some answers to your questions.
 

Wookii

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It’s good to be sceptical. Some answers to your questions.

I've always found that site a little lacking on the 'Science' element of 'Aquarium Science', and a little too strong on the 'Unsubstantiated opinion' element.
 

dw1305

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Hi all,
I wonder who stands behind 'Aquarium Science'. I know something about home experiments. They are rather costly, and above all, time consuming. I wonder who could possibly perform so many tests as an amateur? True, the author does not insist to be an amateur. If he/she is a pro, then crucial question arises: who pays for that?
It is mixture of <"the good, the bad and the ugly">. He isn't great on planted tanks, but the sections on <"biological filtration"> are pretty good.

I don't know anything about his background, or motivation, but I'm reasonably convinced that it is <"genuine and bona fide">.
It routinely attacks all commercial products
<"Not all of them"> and some sections <"are just fantastic">. I really like the <"comic potential">* of a <"properly angry person">.
......Another ceramic product which is the same as all the others is Biohome. This ceramic media is heavily marketed by a YouTube guru called the “Pondguru” from the United Kingdom. If I want a laugh I watch this snake oil salesman’s videos..........
a little too strong on the 'Unsubstantiated opinion' element.
That is partially why I think it is bona fide, if he wanted to peddle an agenda he would need to tone down his approach. He can be a bit "shouty".

* I did apologise to @Miss-Pepper

cheers Darrel
 
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Yugang

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Hi all,

It might depend on the grade of activated carbon you use.

I actually <"go out of my way"> to make sure the water always <"has some tint">.

I think if you keep <"Lake Tanganyika surge zone Cichlids"> then you might want clear water, but for everything else I'm pretty sure that some humic substances <"are an unalloyed good thing">.

cheers Darrel
I am trying to understand this, I obviously miss the point of using this.

I can imagine for industrial scale processes, activiated carbon is the solution. They can't simply replenish 50% of their huge weekly volume with a couple of buckets tap water.

But for a planted tank, when you can easily change 50-80% water per week, where plants and fish will love you for that? Why not just do the obvious, and bring in clear and clean tap / RO water?
 

dw1305

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Hi all,
But for a planted tank, when you can easily change 50-80% water per week, where plants and fish will love you for that? Why not just do the obvious, and bring in clear and clean tap / RO water?
<"Totally agreed">.
I'm a fairly fanatical water changer (small percentage change every day),
I'm a <"rainwater user">, but I wouldn't have any issue with <"using our tap water">. I have some <"environmental concerns"> with RO water.

The only "problem" with the advice to "change some water" is that nobody <"makes any money out of it">, and unfortunately our hobby seems to <"suffer disproportionally"> from <"Snake Oil"> salesman.

If I have an agenda, it is <"this one">.
.........With any aquarium product I look at it like buying a fitted kitchen, the salesman tries to sell you all these up-grades etc. but when you look at it objectively you have just paid a £400 for a couple of bits of particle board and some cheap fittings. I know enough about photosynthesis and plant nutrition to know that there are no "special phosphors" in fluorescent tubes and that every NO3- ion is the same as every other NO3- ion in solution, and if any-one tries to tell me different they are wrong.

I may have a jaundiced view, but look on the companies that sell these products as a bit like payday lenders, people go to them in their hour of need, and then they keep on using the service. There is no money to be made in KISS solutions and telling people that growing plants and time are all you need, add in a soil substrate and rain-water and you have a virtually free recipe for having a successful tank. However if you can keep peoples tanks continually teetering on the brink of disaster you can carry on selling them "pH buffers" etc...........

cheers Darrel
 
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_Maq_

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But for a planted tank, when you can easily change 50-80% water per week, where plants and fish will love you for that? Why not just do the obvious, and bring in clear and clean tap / RO water?
You can see it also the other way round. If you purchase activated carbon in hobbyists shops, you pay for tremendously over-priced and often low-quality (or unknown quality) product. I've bought a 25 kg sack of industrial AC of suitable (and known) quality for less than 100 pounds. I'm using AC in a ratio of 1 g AC per 1 liter water, and it seems to get exhausted in about 3 to 4 weeks (my tanks are usually low in dissolved organics). So, that 25 kg bag will be enough for many many years.
Do you get tap water or even RO water for free? You don't have to move a finger when doing water change? Is it truly that effortless and environmentally friendly?
That said, I too make water changes, generally 20 per cent a week. But, like I said before, water change and AC do not have entirely the same effect. Use of Activated Carbon, Purigen, etc.
 

Garuf

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Hmmm. My water is faintly urine coloured with no purigen/carbon within a couple of days and straw like by the end of the week without purigen/carbon even now the tank is some months old. Water changes don’t really fix that but I totally understand the point.
 
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