from Facebook: Karen R. on Excel

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from Facebook: Karen R. on Excel

Postby Admin » Mon May 16, 2016 12:34 pm

John Smith
Yesterday at 1:15pm
Does Karen or anyone else still have that collection of links she posted about the toxicity of Glut? I have a friend who is using 10% stuff and has heard the statements but wants actual info. Thanks.
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1Justin Titus

Karen Randall Really, all you need to do is google it... That's exactly what I did. I don't have the info on my iPad, but if I get a chance tomorrow, I will post the links yet again.
Like · Reply · 1 · 17 hrs

Saumya Chakrabarti

here is one study,

2-Week Inhalation Study in F344/N Rats

All males and females in the 5.0 ppm and 16.0 ppm groups died or were killed moribund before the end of the study (Table 3). All animals in the 16.0 ppm groups died on Day 4 of the study; 7 of 10 rats (3 males, 4 females) in the 5.0 ppm groups died on Day 5, and the remaining animals in the 5.0 ppm groups (two males, one female) died on Day 9. Body weight gains of rats in the 0.16 ppm and 0.5 ppm groups were similar to those of controls. Body weight gain for male rats in the highest surviving exposure group (1.6 ppm) was negligible. Female rats in the 1.6 ppm group showed a
slight weight gain during the first week of exposure, but they had lost substantial body weight by the end of the study. Chemical-related clinical signs of toxicity were observed in the 1.6 ppm, 5.0 ppm, and 16.0 ppm groups and included labored breathing, ocular
and/or nasal discharge, mouth breathing, and rough haircoat; respiratory difficulties and ocular and nasal discharge were observed immediately after exposure to 5.0 ppm or 16.0 ppm glutaraldehyde. No clinical signs were observed in rats exposed to
glutaraldehyde at concentrations of 0.5 ppm or lower.
Like · Reply · 1 · 13 hrs

John Smith Thanks
Like · Reply · 12 hrs

Karen Randall Here is my standard cut-and-paste (sorry to those who have read this too many times, but John asked wink emoticon ):

I think there are two different issues involved here. First is the use of generic gultaraldehyde rather than Excel or other commercial products. This is risky business. Read OSHA's safety requirements and ask yourself whether aquarists are handling it this carefully:

Then, if you can wade through it, read this study on exposure in rats and mice. Not pretty:

That's why I am adamantly against people using generic, full-strength Gutaraldehyde. The risks are just too high. This is a known neurotoxin, and every exposure makes adverse effects more likely.

Now, back to Excel, which is MUCH less concentrated, and I believe has a slightly different chemical make-up. As far as I'm concerned as well as some very knowledgeable PhD level scientists, it is actually a mild algaecide, which kills some or all of the microscopic film of algae that grows on plants kept under less than ideal conditions. (if you don't believe this happens, look at a leaf under a microscope sometime) This, in turn allows the plant, itself, better access to the nutrients and CO2 that ARE available within the system. So the plants DO benefit from Excel under some circumstances, but not for the reasons stated on the bottle. I do NOT believe that plants use Excel (OR Glutaraldehyde) directly as a "carbon source".

BUT, if you won't can't provide a source of supplemental CO2 in your tank, Excel (or similar commercial products) CAN help you get better growth. But stick to commercially available products, use in a well-ventilated area, do NOT get the bottle near your face, and do NOT get it on your skin or in your eyes. If you do, make sure to flush immediately and thoroughly in running water. If you develop a rash or respiratory symptoms, contact your doctor immediately.

I don't have anything negative to say about Seachem. They were the FIRST company to really listen to planted tank aquarists and give us the products we wanted. They are "the good guys" in my book. I don't agree with them on HOW Excel works, (based on the work of other scientists at the University of Copenhagen) but as I said, it DOES improve plant growth in certain circumstances. I was a beta tester for the product, so I know as well as anyone how it works.

I have problems with HOW people use it, (at larger than manufacturer recommended doses, which they NEVER suggested) and problems with misinformed people who insist on calling it "Liquid CO2". (again, something Seachem has NEVER suggested)

My BIGGEST problem, and it is due to serious, documented health concerns, is with people who buy and use generic glutaraldehyde just because it's less expensive, and suggest that others do the same, without significant warnings on how to handle a dangerous chemical safely.

Gary Lange I guess I missed this thread the first time around and saw it on Cheryl's "March Clippings". It's one of my pet peeves, the ignorance of using glutaraldehyde and then thinking it's the same thing as Excel. Excel is a crossed linked group of glutaraldehyde molecules so it is not near so reactive as unlinked material, it only has a few "active" sites. However there most likely are still uncrossed-linked molecules in the solution. The fact that some types of fish die from it suggests that. Saying that glutaraldehyde is just like Excel is really like saying a solution of 20 of the known amino acids is just like insulin. Insulin is a cross-linked protein chain consisting of amino acids and no way will you get the same effect with a bunch of amino acids in solution. Whoever made the leap from Excel being equal to glutaraldehyde in the first place needs a really hardy "Gibbs slap" (for all of the NCIS fans) on the back of the head! In the biochemistry lab we use glutaraldehyde to cross-link small molecules that we can't make antibodies to with larger molecules. A reactive glutaraldehyde molecule will do this. When our solution gets too old or some goober in the lab doesn't tighten the lid it eventually reacts with air and then cross-links, it's a slow process in that manner. When you inhale small amounts of glutaraldehyde it cross links your lung tissue. We also use formaldehyde for these sorts of fixing processes and everyone is pretty aware of how dangerous formaldehyde is or they should be. Now the other problem is when you get active material on your skin it can be absorbed and start cross-linking some of your proteins in your skin. Probably not good but most of the time your body just does the repair work and moves on. But you COULD cause a problem where your body no longer recognizes this cross-linked protein and now decides it's a foreign host and this could lead to an autoimmune response. If you dig Lupus, go for it. As someone who worked with it for years in the lab and handled it VERY cautiously (in a fume hood) I think there isn't anything dumber than using glutaraldehyde in your aquarium. I think you would be better using a broken heater instead, at least you would get the instant feedback!
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Re: from Facebook: Karen R. on Excel

Postby Admin » Mon May 16, 2016 12:40 pm

We used Excel on two tanks with problem algae
on the first tank the bad algae was gone in days!
No fish or shrimps were harmed.
The snail population is lower, but some snails survived.
The only plant that had major problems with the Excel was Val.

Excellent article Karen. Makes lots of sense.
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Re: from Facebook: Karen R. on Excel

Postby redpaulhus » Mon May 16, 2016 3:09 pm

I think I read somewhere that the active ingredient in Seachem's Paraguard is also a form of glutaraldehyde -- but I suspect it is also in a safer form than the pure glutaraldehyde that Karen referenced as being dangerous.
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