Using Glutaraldehyde to kill patches of hair algae: so far, effective.

[redfishsc]

In the spirit of experimentation, seeing what works in one system (freshwater), and wondering if it worked at all in saltwater, here is the story--- using glutaraldehyde to kill various forms of "hair" or thread algae.

You must forgive the lack of pictures. My camera's autofocus no longer works well.

Situation:
I have a small mixed reef-- a nano, with no skimmer---- I set up a little over a month ago as just a personal experiment that I'm stocking mostly with either weed corals (anthelia, zoas, etc) or frags of common corals from friends of mine. Got the usual hair algae bloom about the moment the cycle finished (week 2 or 3, started with mostly dry rock). The hair algae has proliferated a LOT more than I expected so this gives me a chance to experiment. Freshwater plant tank keepers know fully well that Seachem's Excel (polycycloglutaracetal) is a very effective hair algae/black brush algae killer. I have a 1 gallon jug of Metricide 14 (a 2% glutaraldehyde solution). Right now it's $30/gallon on Amazon.


I wanted to see if it had a similar effect in saltwater, and it definitely seems to. My hopes--- that this stuff will kill some of the hard-to-kill items like bryopsis, when magnesium treatment like Tech-M is ineffective (it isn't a guarantee!). I do not have any bryopsis in my tank (not the terribly invasive form, at least) but glutaraldehyde should do the trick with it as well.

This tank has no fish and no stocked crustacean life other than common amphipods. The only stocked animals in the tank are corals, 1 turbo snail, and 3 redbanded trochus snails.




Dosing---
I started with a safe (but otherwise random) value of 0.2mL per 10g of water. Each day I ramped it up by another 0.2mL. Once I reached a 1.0mL per 10g, I stopped increasing the dose because my frogspawn started doing very odd things (see below). I am now on day 3 of the 1.0mL per 10g and this is the max amount I will dose.




Results thus far: Spot-treatment is the best rout----
Dosing the full 1.0mL onto patches of the hair algae causes it to bleach out by the next day. However, the good news is that the hair algae all over the tank is looking more "brown" now than green. The snails seem to have an easier time attacking the bushy spots and mowing it down-- you can see where they have been on the rock.

For fun, I actually "spot treated" my green star polyp frag. It immediately withdrew, but now (3 hours later) it's open and acting normally-- no apparent damage (yet, will report later).




Corals and other animals that show NO reaction, negative or positive, after the first week.
Montipora "Idaho grape"
Montipora digitata "orange"
Misc green/brown Acropora
Green Acan echinata
Most zoanthid and paly species
Green star polyps
Anthelia

Snails behave normally--- 1 turbo and 3 redbanded trochus snails. They appear to be able to eat larger clumps than normal, and this is actually seen in freshwater tanks as well. Black brush algae will turn pale pink, and is then eaten by snails and algae eaters that normally won't touch it.

I have a handful of small asterina stars in the tank that also seem to be doing very well. I've seen NO dead hitchhikers--- bristleworms and small filter-feeding fan worms are doing just fine.



Corals that respond negatively:

"bam bam" zoanthids--- they close up for an hour or two but they are still growing-- they have produced 2 new polyps since I began treatment-- gone from a 2 to a 4 polyp frag.

Frogspawn--- two varieties--- both appear to be E. paradivisa.---- both forms will inflate very strangely within a few minutes of the higher doses. The mouth/disk area will inflate 2-3X more than normal and tentacles shrink. They return to normal afterward.



I will continue this dose until one of three things happens:

1) Algae is all dead and gone (or eaten by snails)
2) Algae proliferates (doubtful, based on what I've seen)
3) Corals start reacting in alarming ways. I'm willing to risk these for the sake of the experiment.

[stormrider27]

Sounds very encouraging Please keep us posted on your results!

[HighlandReefer]

Following along.

I have not looked into the mode of action as to how Glutaraldehyde kills algae. Perhaps you have some insight?

I would not make an assumption that this product can kill the shiphonous algae (Bryopsis) because it kills filamentous algae, especially if it effects the cell membrane like many other biocides do. This is not to say that it won't kill the siphonous algae though. What little I have read about Glutaraldehyde, it does not effect higher plants. The siphonous algae are kinda in-between the two. I would love to see tests on known siphonous algae as well.

Thanks for sharing your experiment.

[HighlandReefer]

From this selection taken from this book, the mode of action is thought to be due to the formaldehyde release from the Glutaraldehyde, which deactivates the proteins (amino acids) in the outer portions of the cells. If the siphonous algae can heal these areas quick enough like they do holes in their membranes, the effect may be quite a bit less. Using Glutaraldehyde may be basically the same as using Formaldehyde.

The Mode of action starts on page 263: This reaction is covered under Agents that React with Acetylacetone:

http://books.google.com/books?id=ri6...gae%22&f=false

[HighlandReefer]

FWIW, Formaldehyde is found naturally in most marine algae and to a higher concentration in Ulva and Halimeda which are siphonous, calcerous algae.

[redfishsc]

Originally Posted by HighlandReefer

I have not looked into the mode of action as to how Glutaraldehyde kills algae. Perhaps you have some insight?

Yeah I have no insight whatsoever other than the observation that it causes it to turn stark white (in my reef, with the variety of hair algae I'm dealing with) and that turbo and trochus snails seem to like to munch on it more than the non-nuked algae.


Your formaldehyde theory is as good as any I could offer. But if it won't kill bryopsis as easily, that would be disappointing. Of course I'm not about to introduce that #^@#$%!#$T^@#&^ stuff into my tank just to find out lol.

If I know anyone locally that has it and is willing to experiment, then I'll give them some glut and see what happens.

[disc1]

Just a side note that goes with any algae killing strategy.

If you kill it in the tank and it either rots or is eaten in the tank, then the nutrients stay in the tank and the algae will return.



Any thought to the effect of the glutaraldehyde on the beneficial bacteria in the system? I know it is a potent disinfectant and is quite toxic to bacteria.

[J. Montgomery]

I hate to break it to you, but formaldehyde and gluataraldehyde are both aldehydes capable of carrying out the same cross-linking reactions.

I'm surprised that adding glutaraldehyde has not caused problems.

[redfishsc]

Originally Posted by disc1

Just a side note that goes with any algae killing strategy.

If you kill it in the tank and it either rots or is eaten in the tank, then the nutrients stay in the tank and the algae will return.



Any thought to the effect of the glutaraldehyde on the beneficial bacteria in the system? I know it is a potent disinfectant and is quite toxic to bacteria.

Agreed. However I think this might be useful for combatting other forms that will grow regardless of the nutrient levels. I've had bryopsis growing in tanks that, for month after month, had 0.0 ppm readings on low-range nitrate and phosphate kits. The bryopsis was slowed, and remained (somewhat) limited to 4 or 5 distinct growing patches that would either sit stunted, or grow very slowly, but never actually recede (even using the famous Tech-M bomb repeatedly).

If, in these situations, we can't remove the infected rock for nuking/cooking, then maybe target-feeding some glutaraldehyde to that patch can wipe it out. Or not.

Originally Posted by J. Montgomery

I hate to break it to you, but formaldehyde and gluataraldehyde are both aldehydes capable of carrying out the same cross-linking reactions.

I'm surprised that adding glutaraldehyde has not caused problems.

Thanks for sharing that. I actually was aware that this was a very similar chemical to formaldehyde (well, that's nearly what it's called).

I did start out at a very low dose, literally just a few drops in a 10g tank with minimal amounts of livestock, and thus far nothing has died except the algae.

Even green star polyps did just fine, taking a full direct shot (maybe 0.5mL) of this. I wanted to see what it would do to it, and the GSP retracted immediately. But came back out surprisingly quickly. That was yesterday. Today it still looks fine. I won't say it's out of the woods yet but it's looking good.


What does surprise me is that the SPS (acropora and montipora) has shown absolutely no response to this at all. All 4 of the frags are polyped-out as normal, and don't recede any when dosing even the 1.0mL per 10g.

[Raul-7]

We usually substitute H2O2 for glutaraldehyde to kill all types of the stubborn algae in FW tanks (I don't SW has a black brush algae equivalent?). It is cheaper, locally available and it breaks down into harmless oxygen and water.

My only concern is how corals will react to it since it is a strong oxidizer.

[redfishsc]

Originally Posted by disc1

Any thought to the effect of the glutaraldehyde on the beneficial bacteria in the system? I know it is a potent disinfectant and is quite toxic to bacteria.

Sorry I missed this question.

Freshwater aquarists have been dosing this (in the form of Seachem Excel which is said to be polycyloglutaracetal) in much, much higher doses than I'm putting in this 10g, with no apparent negative result on the bacterial colonies. Obviously we have no way to measure actual bacterial loss other than checking ammonia, but I haven't even been testing ammonia since the tank cycled. The thought of losing the bacterial colony hand't crossed my mind.


In my 45g planted tank, which as a pretty heavy fish and feeding load, I was dosing a full OUNCE of this stuff every day, which is roughly 30-50% more than my 11g reef is getting. No negative effect to be seen.

I've reduced the 45g planted tank's dosing to about 1/3 ounce daily as a "carbon dioxide" replacement--- the higher plants seem to benefit from it quite nicely. I've noticed more growth in the cryptocoryne and (oddly) java moss since I started the dosing. It's also decimating the patches of black beard algae that were half the reason I started dosing. In a freshwater planted tank, as long as you have a cheap source and understand the basics of dosing a potentially lethal fish killer, it's a win/win situation.

The fish come to the stream of stuff as I squirt it in the tank, they don't seem to mind it at all. I try to avoid them but there's just too many fish in that tank to keep them from playing in it.

[redfishsc]

Originally Posted by Raul-7

We usually substitute H2O2 for glutaraldehyde to kill all types of the stubborn algae in FW tanks (I don't SW has a black brush algae equivalent?). It is cheaper, locally available and it breaks down into harmless oxygen and water.

My only concern is how corals will react to it since it is a strong oxidizer.

Good point, and the only reason I went with glut on my planted tank was because I wanted to see how effective it is at providing carbon for the plants in lieu of compressed CO2. So far so good,--- it's definitely not as effective as pressurized CO2 but way better than nothing.

The H2O2 thing is a very effective means though.

I'm surprised at how the coral react (or, lack thereof) to the glutaraldehyde, but then again I will NOT go over 1.0mL per 10g based on what I see my frogspawn doing. No need in tempting fate anymore than I have.


Does SW have a bba equivalent? Kinda sorta but not really. Bryopsis is every bit as invasive and actually more difficult to kill for many folks. I'm sure someone will quote me here and say it's way easy to kill because of "ABC123 that worked just fine for me!" but in reality bryopsis has caused a bunch of folks to just tear down the tank, douse their house with gasoline, and light it up.

Unfortunately, HighlandReefer has pointed out that bryopsis may not be affected by glut, so even if I prove it to be useful against lower forms of thread/hair algae, it may not be against bryopsis forms. And I'm not about to put bryo in my tank just to test it lol.

[HighlandReefer]

It would be nice to have something that works on Bryopsis and other siphonous algae that won't hurt the coral and other reef occupants. Perhaps someone that has Bryopsis on rock just starting up will try this or someone that is ready to give up.

[Eric the half-bee]

Interesting. I've never thought of using glutaraldehyde/formaldehyde outside of the lab. In the OR, its used to sterilize equipment and I always was cognizant of the carcinogen/mutagen power of these agents.

[dwd5813]

Originally Posted by Eric the half-bee

Interesting. I've never thought of using glutaraldehyde/formaldehyde outside of the lab. In the OR, its used to sterilize equipment and I always was cognizant of the carcinogen/mutagen power of these agents.

yeah this caught my eye as well because that's what we use for reprocessing endoscopes. i would think that it would do damage to the bacterial population in the tank.

[redfishsc]

Originally Posted by HighlandReefer

Perhaps someone that has Bryopsis on rock just starting up will try this or someone that is ready to give up.

That was me, about a year and a half ago. That issue, combined with some other strains at the time, led me to take down the reef system I had and just focused on LIFE.... and fiddled around with a low maintenance freshwater setup.

Now that I'm back into the "nano" reef game, I'm only doing low maintenance stuff and experimenting as it strikes my fancy.

Originally Posted by dwd5813

yeah this caught my eye as well because that's what we use for reprocessing endoscopes. i would think that it would do damage to the bacterial population in the tank.

The first time I saw "glutaraldehyde" I thought it said "gluten aldehyde" which sounds like something you'd find in cheap bread.

Anyhow, so far it doesn't seem to do noticeable damage to the bacterial population at the dosing levels we are using.


By the way, you just reminded me that I am not using the glutaraldehyde in the same "formulation" that you all use for sterilization------ One thing I need to make clear that I totally failed to do in the first post (which I wish I could edit!!) so I'll make it very visible:

DO NOT ADD THE CATALYST TO THE METRICIDE/GLUTARALDEHYDE

I do not know what happens to the glutaraldehyde when you add the catalyst that comes with it, but I do know that we skip it in the planted aquarium world, and I am using it NON-catalyzed.

[redfishsc]

Day 5, algae still slowly receding and also being eaten by the snails. I'm not so sure the algae is dying and deteriorating much---- I think it's just making it more palatable to the snails. They absolutely have a preference for eating the places that were spot-treated with the glutaraldehyde the day before.


Today I spot-dosed some of the glutaraldehyde directly onto an Anthelia frag. A couple polyps retracted but within a few minutes all was back to normal. The GSP that I spot treated a couple days ago has suffered nothing whatsoever.


I think this can be a useful treatment, but it's use is going to be limited. Obviously not a miracle cure because it's only speeding up the usual decline of hair algae in the presence of herbivores and through good water quality management.

[redfishsc]

[HighlandReefer]

You're only allowed one double post per month.

[redfishsc]

Originally Posted by HighlandReefer

You're only allowed one double post per month.

I only did one double post!