I have a 100 gallon planted tank with Florida gars, an arowana, and a few other fish, and I developed an unsightly infestation of the black variant of brush algae. This algae is very hard to remove even from hard surfaces, grows where there is no excessive nitrates or other nutrients, and is very hard do manage. I would have small Siamese algae eaters, but my gars would eat them, so I have now added copper sulfate to the tank because I hear that this is the only real sure way to kill it. I am using this med as directed, but I wonder how it really affects the general and long term health of my fish. I haven't found anyone who has had experience with this, so here I am. Any experience or knowlege would be appreciated. Thank you. Garman

Copper sulfate at the right dose can certainly kill algae. It also kills snails and other invertebrates. It can harm sensitive fish and even kill some of them, mostly those without scales. I don't know how tough your fish are but I personally wouldn't risk it. At the dosage of copper sulfate used to treat parasites, they will probably be safe. Copper sulfate may also harm more sensitive higher plants. The algae may be unsightly but it's not harming the fish. There are some algaecides that are less nasty than others. AlgaeFix by Aquarium Pharmaceuticals is the only true algaecide I trust to use with fish. I've used it with my huge pleco and goldfish in the past (for suspended algae). You can try some natural remedies such as a mesh bag of barley straw in the tank (near moving water like in the filter).

My algae page is at http://www.fishpondinfo.com/plants/algae.htm

Good luck!

How about dojo loaches? I guess I should post subsequent posts on the algae site, but don't you think the dosage indicated for parasites is enough for brush algae? I'm able to move all my fish to another tank if I need to up the dosage. Do you think this metal would make the fish act sick in the beginning, or is it something like heavy metal poisoning where the damage would be long lasting and not show up until permanent damage is done, even after all the copper is flushed out? This is day 2 and I'm monitoring the ammonia and nitrites,(none) and all fish seem fine.

I think dojo loaches are scaleless? If so, the copper sulfate may harm them. The fish would show acute poisoning if too much copper were added. I suppose they could become chronically ill if it were used long term at lower doses as well. When you're done using it, do a 25% water change and add fresh activated carbon to the filter to remove the leftover copper. Let us know if it works to kill the algae and if other plants or animals are affected.

Ok. I'll take out the dojos and put them in another tank. So you don't know if the amount of copper indicated for parasites is enough to kill brush algae? I totally would have gone a more natural rout if this were not such a difficult to remove algae. I already removed 90% of the leaves on my plants that were covered with this algae, I've cleaned the gravel very well also after having removed the plants and bleached the wood and rocks, and I even cleaned under the end UG filter plates. I introduced the brush algae when I put a lilly pad plant in the tank from a coy pond. I've been doing regular water changes, have at least 5X the filtration recommended, keep the pH at 7.0, and the other waste products at zero, and I even have phosphate absobing product in my filters. I guess there isn't much information out there on using copper sulfate as I have asked about it on 2 other forums and done other research as well. Thanks for your advice. Garman

Day 3 report: No noticeable death of algae, no change in fish behavior, no change in plant growth which is good (Java moss is growing, anubias and sword seem fine), no ammonia or nitrites, and snails still alive. pH is 6.6. About 1 month ago the algae was physically cleaned by removal of the wood, rocks, and filter equipment and scrubbed with diluted bleach solution, and well rinsed before their return. The pH was low, about 6.0 when the algae was growing, and I read that the black variant of red brush algae, which this is, is usually found in low pH environments. Since my tap water is alkaline, I've been able to keep the pH around 7.0 with more frequent water changes, and I've added Phoscheck to me canister filter. Since the cleaning, keeping pH around 7.0, and addition of Phoscheck, I haven't seen the little algae left spread, grow, or die for that matter. It may be that the changes I did prior to copper tx was enough to favor plant growth and not algae growth. There has been and still is a small amount of green algae growing on the glass and this isn't a problem and is easily removed.
I added the copper because I was trying to kill this brush algae before it came back full force, but now it seems I haven't added a toxic enough amount(though it isn't spreading, it's not dying). I will do a water change to bring pH from 6.6 to 7.0 today and start to dilute the copper. I'm not comfortable with the idea of poisoning my fish which are hard to come by and very special to me, so for now I'm just going to work at dilution and removal of copper. If algae starts growing back I'll try a different approach with nutrient regulation instestead.

Sorry, I don't know the best dosage of copper sulfate to kill algae (but not harm the fish). I think the dosage for parasites is about as much as you want to risk with the fish though. Be careful with bleaching wood. Even if you then soak in dechlorinator, the wood may leach out bleach later.

At least the algae seems to have stopped spreading. It's too bad you can't add algae-eating animals since you have large predatory fish. Would they eat/bother snails? The trapdoor snails eat many kinds of algae (not guarantee with that kind) and won't normally eat plants. They are slow breeders. Most other snails will eat your plants first.

I have a population of Malaysian trumpet snails in my other tank, and a few in this one. I'm hoping to get a bunch going as they are pretty gentle on plants and help clean the gravel. I think from what I've been reading on plant geek forum that the key to combating brush algae other than SAE's is controlling nutrients.