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glutaraldehyde instead of excel

156692 Views 258 Replies 78 Participants Last post by  Aquaticz
Hey guys

Last week I have been using glutaraldehde in place of excel.I'm using a 2.8% solution.It's suppose to be about the same as excel but alot cheaper.I paid $16.95 a gallon.

I tried it in two tanks,a 10 gal. planted and a 60gal. planted.
It had a different effect in each tank on some of the same plants.Below I'll list each tank with the dose and effect I noticed.

60gal.,192 watts,11hours lights on,co2 injected,ferts daily,plants are red tiger lotus,rotalia indica,sword,ludwigia,anubias,hair grass and crypts,34 fish.

I dosed 30ml 9/23/6 after a water change then 10ml daily.
On 9/25/6 the angelfish spawned so it seems to have no effect on the fish.
9/27/6 the sword plant started growing fast.3-4" growth of new leaves daily.this plant has not grown much in the last 3 weeks.

It's been a week so far,water is clear,plants are growing fast and the little bit of algae I had is gone.

riccia is ok.

Now for the 10gal.,30 watts 8-10 hours,no co2,ferts daily,plants are sword,red tiger lotus,ludwigia,and bolbitis,tiger barb fry,cherry shrimp and alot of hair algae.

I dosed this tank heavier to see what would happen.
5ml daily.
9/23/6 dosed at 10:00am and by 7:00pm algae shows signs of and shrimp are fine.

9/24/6 riccia is dying off.All the algae are fine.water is a little cloudy.

9/25/6 water is clear.I have a few strands of moss in this tank.I think it's java moss.It is growing very fast.

9/30/6 moss has grown around 10" this week.this moss has been in here for 8 months without much growth.The bolbitis is a little darker green and the leaves have widened.Looks healthier then it ever has.

Other than the riccia dying and the water turning cloudy one day it seems to work well.

If I notice anything else I'll add it to this post.

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The MSDS at Seachem clearly states that the major chemical in Flourish is glutaraldehyde. I doubt there will be long term effects with the use of only a 2.5% solution of glutaraldehyde

I think the increased concentration of glutaraldehyde is responsible for killing of 'fragile' algae when people dose 2x-5x the regular dose to get rid of algae.
I was reading some companies MSDS sheet for it and it mentioned something like 'toxic to aquatic life in at .1 to 1.0mg/l for the most sensative species'. They never mentioned the species but a guess is that the cloudy water some get with high doses of excel is due to a die off of bacteria.

If I have done the math right (I probably have not;) ) then a 30 ml dose of 2% solution in 60 gallons is .26mg/l, pretty low on their "toxicity scale". That would lead me to belive that the most sensative organisms would be affected. Higher dosing woudl robably affect shrimp or snails, and lastly fish.

Using the same math, 5ml in 10 gallons is about .3mg/l. As I said though, I may not have converted to mg in a 2% solution correctly. I based my figuring on 100g/mol, or 10^5 mg/mol and assumed that one could figure a 2% mol solution in 1liter H2O. Please tell me if I am wrong.
Assuming the 2% is weight-by-volume: 2% w/v = 2 grams / 100 mL

30 mL in 60 gallons:
(2 grams / 100 mL) * 30 mL = 0.6 grams in 30 mL of the 2% solution.
If you add it to 60 gallons of water, 60 gallons * 3.78 L / gallon = 226.8 L
0.6 grams / 226.8 = 0.26 mg/L

5 mL in 10 gallons: (Still 0.26 mg/L since the solution volume and tank size are both 5 times smaller)
(2 grams / 100 mL) * 5 mL = 0.1 grams in 5 mL of the 2% solution.
Adding it to 10 gallons = 37.8 L
0.1 grams / 37.8 L = 0.26 mg/L
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Urea instead of KNO3, KPO4, and KSO4 (if a K supplement is needed), and trace with Plantex CSM+B.

This should be interesting. =)
Urea - Science Kit and Boreal Laboratories seems pretty cheap, compared to a place like this: Urea, FCC

Seems like these stores carry pure urea crystals as well as prilled urea (pellet form). I don't know how pure the prilled form is, so let's assume I get the crystal form of urea.

2.5% urea = 2.5 grams / 100 mL water
mL water required = 500 grams * (100 mL water / 2.5 grams) = 20,000 mL = 20 liters

From the cheaper site, for $15.50 plus shipping, you can get 20 liters of 2.5% urea!! Heck, if the prilled form was water-soluble and pure, it'd only be $8.70 plus shipping for 20 liters.

Urea crystals, if stored in a dry environment, aren't prone to decomposition, while urea solution is. So of course you shouldn't mix up all 20 liters, maybe a couple hundred mLs at a time.
Glutaraldehyde - The Highest Purity

25% solution
0-18ºC 16220 Box 10x10ml ampoules 21.00

You can do a 1:9 dilution (10 mL glutaraldehyde to 90 mL of water) to give you 100 mL of 2.5% solution per ampule. That's 1 liter of glutaraldehyde for $21 + shipping. Although some other places might sell bulk for less (not sure, haven't checked) this type of packaged glutaraldehyde is preferable since each ampule is packed in inert nitrogen so there's no breakdown or adverse reactions since it's not exposed to air/oxygen. You can mix up 100 mL batches and dose them as needed so you won't waste much of it.

Heck, if you have larger tanks...
0-18ºC 16521 50% Solution 4x1 liter 67.00

1 liter solution to 19 liters of water will give 20 liters of a 2.5% solution. This is 4x1liters of glutaraldehyde, so you'll get 80 liters. For $67 + shipping. Less than a buck per gallon!

I'm not sure why the riccia is dying. Are you dosing straight into the tank? I suspect that if the entire bunch of riccia is being hit with too concentrated a solution of glutaraldehyde, the fine plantlets won't be able to recover & will die slowly. Try to add the glutaraldehyde in a very diluted form.

Allen, you said the riccia died slower in the 60 gallon tank. I think it's because as you added the glutaraldehyde, it was more easily diluted in the 60 gallons before it hit the riccia as opposed to the 10 gallon tank.

Maybe when you do a WC next time, add the dosage into a bucket of water instead of dosing straight into the tank. Or you can try adding a bit at a time, throughout the entire length of the tank and avoiding the patches of riccia?

I'm looking forward to the remainder if your experiments!
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Google cache. I can't find the original thread. Or rather, haven't looked for it. :: View topic - Effects of Seachem Flourish Excel on BBA


The effects of Seachem Flourish Excel on BBA were documented with images and texts. It shows that Seachem Flourish Excel caused the BBA to turned red within 24 hours. The BBA gradually turned white over 120 Hours and disintegrate slowly thereafter.The experiment shows that Seachem Flourish Excel has successfully eliminated BBA. We would advise that Seachem Flourish Excel should not be use as a permanent way of removing BBA, as solving the root of the problem is the key to prevent future outbreak. We realised that Flourish Excel should not be used in large amount on mosses, riccia, and fissidens. It may cause them to turn brown or even kill them.

So MatPat, high doses of Excel *will* kill riccia. =)
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After looking in the CRC handbook for possible polycyclo compounds, I'm guessing the side-chains in the polycycloglutaracetal (active compound) of Excel seems to make it less toxic. Not sure if the cyclo side chains actually allow for more carbon molecules per molecule of the polycyclo compound, but it makes the compound less toxic and/or prolongs the shelf-life.
Tony, I'd be interested in helping you figure out what's in it. I might grab a bottle sometime and run GC-FTIR-MS on it...unless you beat me to it. =P
Awesome. Hope the riccia does well. =) I'll be checking this thread often!

Take before and after pictures, especially of the riccia. Then we can really judge the growth rate when using glutaraldehyde.
2.6mg/L, I stand corrected. Thanks. =)

I multiplied by 100, not 1000.
I did not mean to "correct" you but it was throwing me for a loop. Math and chemistry are not my best subjects so I did not realize how much a 15ml dose adds:) My bad. Good news is that tetras, nerites and pygmy cories can take 3.75ppm gluteraldehyde. Riccia is not to happy and BBA may be a bit grumpy but the plants and fauna are fine.
How are you adding the glutaraldehyde to the tank? Maybe if you had enough riccia, you could do a few experiments.

Have thse following groups of riccia:
1) Free-floating
2) Tied to a rock closest to the area where you dose your glutaraldehyde
3) 6 inches away from rock #2
4) 6 inches away from rock #3...and so on so forth.

This way, we can see if the initial "shocking" concentration of glutaraldehyde has anything to do with its death, or if the overall concentration of ~3.75ppm is enough to do it in. If we can figure out what's actually killing it, we might be able to find a good way to dose the glutaraldehyde. ie: Maybe mixing it with new water during a WC and adding it that way, or adding it as the water flows in from a python or something similar.

That's what I was thinking. Maybe if the glutaraldehyde gets mixed up a little more before it's added to the tank, it wouldn't kill off the riccia. What if you added it close to the outflow of your filter, or close to any powerheads you might have?

ppm = mg/litres of water.
15 mL * 2.5 grams / 100mL = 0.375 grams = 375 miligrams.
ppm = 375 miligrams/97 liters = 3.87ppm.

I wonder how many ppm of glutaraldehyde-equivalent is in Excel.
I do add it basically into the flow from the filter. What is interesting is that the riccia at the far end should get the most concentrated amount of glut but is the stuff in the midle that is affected. So, either its a result of the higher light in the middle or the gluteraldehyde settles faster through the water than it mixes initially.

I don't think we'll ever find out how much is in excel, and understandably so.
If we can atomic spectra on Excel, we might be able to figure out what it is....after that, I'm sure we'll be able to do something. ;)

I wonder if this counts as violation of any intellectual property laws. Hm.
According to Seachem they use a different isomer of glutaraldehyde than the common form used in hospitals.
Yep. I think it was mentioned somehwere in this thread already. It's a polycycloglutaracetal. Nothing more than a few cyclic rings added on to your conventional glutaraldehyde. I was just wondering if "reverse engineering" this structure would be in the legal realm.
Soo.... Excel is just modified to make it less toxic?

Has it been modified in any way to make it more effective at giving CO2 to plants than glutaraldehyde?

Also, does anyone know if Excel is pure? Or is it laced w/ other chemicals?

I was thinking about running some lab tests on it to see how it is put together in the hopes of gaining an idea of how to make it, but I need a pure sample in order to run the tests.
No, it's not pure, it's combined with "ameliorating" chemicals.

You can try to distill it and then run GC-MS or whatever you want on the separate fractions that are collected.
I hadn't given any consideration to the ameliorating chemicals. Without a pure sample of the main ingredient of Excel, any of these methods would give spectrums that would be impossible to figure out.

IC would work to see the functional groups and they're relative abundancies, you're right. MS would give common m/z groups which will lead to a better understanding of the actual structure of the compound. NMR would give even more information about the proximities of the carbons and functional groups to each other.

Even if we did manage to get "pure" Excel, figuring out the structure wouldn't be such a simple task given our limited resources to this equipment.
Hi everyone

I haven't posted anything here for awhlie because I've been playing around with the glut.

I've been adjusting the doses and found that 1ml to 1 gallon of water at a water change does not seem to hurt the fish,plants or bio filter along with a 1:2 daily dose.This will slowly kill the algae.
For a more severe algae problem I can add 1:1 three days after the 1:1 at water change.
A 1:1 daily dose seems to stress the fish.Plants are fine but it will destroy the bio along with the algae.
A 1.5:1 will kill the fish.
Once the algae is gone I reduced it to 1:5.The plants are growing as fast as they are in the tank with co2.
This is what has happened in my tanks and it might be different for your setup.

I haven't tried a dip for new plants yet but it might be a way to kill the algae and those #%@* snails & eggs before placing them in the tank.
Eric,I should've tried this with that red rubin I got from you.Oh well,the loaches are happy,their bellies are full.

Has anyone else tried this stuff?What kind of effects has it had on your plants?I'm sure others would like to here about it.

As with all chemicals please use with caution and if you do a search it's easy to find the MSDS for glutaraldehyde.
Af far as snails go, I'd try a concentrated salt water bath instead of glutaraldehyde. But if you're worried about both algae and snails, then a dip in glutaraldehyde will probably get rid of both if the problem isn't too severe.
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