View Full Version : Let's talk about algae

11th August 2009, 16:40
Hi all,

I'm having the devil of a time with algae. There are many possible factors contributing. Since we moved to the new house in October, the tanks get a lot more light as the room is sunnier. Since I got a puppy, I haven't been doing weekly water changes, but only roughly every 10-14 days. I have also added lots of plants, some of which I bough at trade shows and a few of which I am certain were contaminated. (Thinking here of "brush algae" if it's called that in English, evil black threads that anchor onto plant leaves.)

Unfortunately, I can't seem to erradicate the beasties.

First I thought, give the plants time to establish themselves, and they will take the nutrients away from the algae. No go, the algae are covering the plants.

More frequent and even drastic (>30%) water changes have had no effect. Nor have removing infected plants, scrubbing affected decorations, removing the "blue algae" (a carpet-like thing with a color I didn't know Nature could create), decreasing or eliminating all artificial lighting, decreasing amounts of food, increasing numbers of snails or shrimp.

My most problematic tank (I have five in all, with varying degrees of algae growth) is the one with the least amount of light and the fewest animals - and the most plants. This lucky aquarium boasts at least four types of algae: the "brush", the "blue", something they call "thread algae" in German (actually kind of pretty and mossy looking, long green threads that grow into a soft mass that clings but does not root to anything it finds), and that brown stuff that accrues on the glass.

Although I am tempted to drain the whole aquarium and start over, I reckon that if I can't find the problem, I will be back at this point again eventually, as the basic conditions will not have changed.

Although I would really really love to have some little medicine that I could dribble into the tank and kill the lower plantlife, I obviously doubt that I could add anything that would not affect my skin-breathers.

This thread has gone on for long enough so I'll be glad to answer in more detail to specific questions - but does anyone out there have some advice for me?



11th August 2009, 18:19
Ok. So let's start with what I know from my fishkeeping experiences.

1.) Brush algae is a true pain. Nothing will eat it, and it grows more quickly than a lot of low-light plants, so it'll overtake leaves. Remove affected leaves/plants, and address water quality/lighting issues that foster it.

2.) that hair algae you're talking about is actually pretty easy to remove manually. Since it doesn't root/cling, you should be able to pick it out by hand. You might have to throw out a plant or two if you really can't dis-entangle it.

3.) brown algae: scrub. Scrubbing the glass might be your best solution.

A few things inspire algae blooms. Do your tanks get any direct sunlight? That's the most likely culprit. Too much artificial light can have the same effect. Sometimes, shortening the day cycle gives the plants time to re-assert themselves in the battle for nutrients, thereby killing off the algae. Excessive nutrients (overfeeding or poo) also lead to algae. Change tank water more frequently.

In fishtanks, there are a number of fish that remove algae, none of which would be compatable with axolotls, as they're all catfish, which have some manner of armor/spikeyness. Plecos (which get huge, so you probably don't want to rehouse them), bristlenose plecos, or a school of otoclinus MIGHT eat their way through some of the algae (though not the brush algae or brown algae). You would have to temporarily rehouse the axolotls, ensure the fish were healthy (quarantine), and leave them in the tank long enough to do their thing. (You'd also have to bring the tank temp up, as they're all tropical, and so you'd want the water to be ~75.) Then, you'd have to rehouse them. (Petstore might take them back, but I wouldn't expect a refund.) The only other way to do it would be to break down the tanks, sterilize gear, and chuck plants, and start over. The algae shouldn't be harmful to the axolotls, though I'd worry about gills getting stuck on hair algae. If you don't address the underlying cause, (too much light, too many nutrients), it'll just be back, anyway. If you're sharing equiptment (water vacuums/tubing) that might be how it's spreading among the tanks.

If I were in your position, I'd remove all that I could, manually, decrease the light cycle, make sure no tanks were exposed to daylight, (which might be enough on its own), and then try the above catfish plan, but I also have an established tank with algae-eating fish that I know are healthy, so that makes it a little easier for me to do.

Algae can be such a pain. I hope it works out.

12th August 2009, 02:17
Hi Eva!!

I havent had algae in my axies tank, so I have no experience dealing with it, but was thinking maybe taking out your plants and put them in a bucket and add somethig to kill the algae?

I was thinking killing algae in the tank would add bioload so there is more food for remaining algae.

I have read flourish excel can kill algae, or some potassium permanganate?

12th August 2009, 11:48
Have you tried testing for water phospate levels?

12th August 2009, 11:55
I find that what works is to add competition. If you heavily stock your tank with fast growing plants such as elodea, they will compete for nutrients. However im not sure axolotls and heavily planted tanks are the ideal mix...

12th August 2009, 12:06
I have had success treating filamentous and brush algae with barley straw. (This is a technique I stole from folks with ponds.)

This product is commonly sold for treatment of algae in ponds as a floating mat. I purchased the smallest one I could find, then cut it into small squares. The catch here, is it prevents the growth of new algae, it will not kill existing. This in addition to regular tank maintenace and a bit of work with a scrubber every so often, will keep algae growth to a minimum. Over a period of months it is possible to nearly eradicate most types.

With "Brown" algae, I have never been able to get rid of this diatomaceous mat. A tank scrubber made for the purpose controls it well.

Here is a pretty good paper on the barley straw:

Aquatic Plant Management: Barley Straw for Algae Control (PDF) (http://www.btny.purdue.edu/pubs/APM/APM-1-W.pdf)

12th August 2009, 13:04
I have read flourish excel can kill algae, or some potassium permanganate?

Flourish Excel is actually really cool in that it kills algae and enhances plant growth. This product is made up of glutaraldehyde which plants can use in glycosis to produce energy but that algae cannot fully utilize where it become a non-specific inhibitor of glycosis of normal products.

Of course, glutaraldehyde is known to be toxic to fish in large doses so I imagine it would not be good for axoltols and would probably cause some sort of damage.

I'd recommend removing all direct sunlight if at all possible. Try keeping the curtains closed during the day or set the tanks so that they don't receive any direct light. The sun is a powerful stimulant to plants, far more than any bulb. Adding fast growing plants is also an excellent idea as they will soak up excess nutrients that the plants you have now (which may be slower growing?) don't get a chance to utilize. You can always throw away the rampant plant growth.

The main thing is you really do need to get your hands dirty to beat this. Scrape the glass with a razor (wash in alcohol first to remove the oil/grease they coat them with) and manually pull out balls of hair algae.

13th August 2009, 10:27
Hi all,

Thanks so much for the tips. I will see if I can get barley mats here in Germany.

Here is my puzzle: I have four tanks in the same room, two on the western wall bracketing large windows, one on the southern wall, and one on the eastern wall. The windows on the eastern wall are the only windows in the room. Light is bright diffused, dappled by an ancient red beech.

The tank on the southern wall receives 4 hours of articifical light daily. This tank has no algae whatsoever but that is not surprising as it is my breeder tank for guppies, snails, and shrimp.

The two tanks on the western wall have the usual brown algae on the glass, but rown algae doesn't bother me at all, it is easy to remove and the tanks are not that heavily affected. Both tanks have a touch of blue algae (that's the psychodelic teal colored mat that forms on the sand) in the corners nearest the windows, which would indicate that light is the main "food" source for the pesky plant.

The tank that is most heavily affected, however, is the one that has the most plants, the least animals, and the least light. It is on the eastern wall across the room from the window and as such receives only ambient light. It had been getting artificial light like the fish tank, but I have since unplugged the timer - to no discernable avail in this battle. The glass panes are literally covered in brown algae, which reproduces overnight after a thorough scrubbing and water change. The tank is full of plants and mosses, al of which are growing well and quickly. Unfortunately the plants themselves are being covered by the blue algae - I don't understand how they can grow at all with the reduced light and then being covered with psycho-slime. The brush algae had spread from plant to plant and I recently cropped everything down to half-height to remove as much algae as possible without removing the other (competitive) plants. The filamentous [thaks for the vocab., Johnny!] algae, I must admit, entered the tank by my own hand because I thought it was a moss and found it pretty and took it from another tank (in another room) and tossed it in. :o This tank is 120x40x50 cm and holds one adult axolotl, two platys, countless bladder snails and a few ramshorn snails, one Amano shrimp and (as of yesterday) three mid-sized Red Fire shrimp. The fish/snails/shrimp get a pinch of food flakes every two or three days and the axolotl gets some worms, some woodlice, etc., once a week. I change the water roughly every two weeks, maybe every 10 days, draining off about 30% of the water and adding fresh (and suctioning out blue algae, pulling out brush and filamentous algae, scrubbing off brown algae while draining).

So the tank that should, according to the hints of too much waste/nutrients and too much light, have the least problems, has the most. :confused:

I bought some aerators and, pending the purchase of long screws and extra tubing, will be adding them to the tanks in the hope that this might help - any thoughts on that?

Thanks so much and sorry for the long post,


16th August 2009, 05:31
That sounds aggravating. Have you tested the water or done any water changes? I would probably have lost all patience and broken the tank down entirely by now. I really do wish I had better advice to give. I hope you're able to save your plants, at least.

16th August 2009, 10:01
I haven't tested the water (I hate fiddling with the tiny bottles and their childproof caps). I simply assume that there are too many nutrients in the water as the algae must be finding something to flourish. I have become very sparing in feeding (with fish flakes; the axolotl never has any food leftover). I change roughly 30% of the water roughly every week-and-a-half, am trying to get more regular at weekly water changes.

It isn't patience that has kept me from dismantling the entire tank and starting over, but laziness. :p


28th August 2009, 03:16
Hi Eva!

How are you doing with your algae problem?

1st September 2009, 07:02
Hi Celeste!

The worst tank is actually doing better. I had had two large hides in that tank, both of them large. I removed one of them because it was covered with algae. I hoped that this would allow the other (higher) plants more room to grow. I had also trimmed all of the plants (mainly Valesneria) down halfway to remove as much brush algae as possible without actually removing all of the higher plants. This tank is looking much better.

Of the other two, one also looks very good; the other has one corner that receives sunlight (filtered by a tree out front) each afternoon. In this one triangle where the sunlight shines directly on the tank, there is still blue algae. The rest looks pretty good, too.

I am thinking/hoping that consistent water changes will be the key to mastering this problem.

I have also purchased some aerators in the hope that providing more oxygen or removig more carbon dioxide (??) I will be making life tougher for algae. I haven't installed them yet, though.


Coastal Groovin
1st September 2009, 07:37
I hate to say it but you should cylce a new tank with a dozen guppies but your axies in it when its done Drain your tanks and bleach everything!! Nets, gravel, stones, pots, everything Rinse well with cold water. It will be the fastest way. And you will keep your sanity. Ive never seen a tank with that many types of Algae ever!!

1st September 2009, 09:26
Hi Bill,

I would be terrified of using bleach! I am guaranteed not to do it right.

I have 4 tanks. I am waiting and waiting for my young males to be large enough not to fit into Axel's mouth. At that point I will have the three males together and disassemble the fourth tank. The "little" ones are juts taking a long time to grow and Axel's mouth is a big one. Axel's is the worst tank.

I wish I had taken pictures of his tank at its worst. It looked pretty cruddy. I am still hopeful, though, to be able to take some pictures of the tank looking good.


1st September 2009, 23:21
If the side of the tank that's getting sunlight isn't the front, viewing side, then try covering it with paper, the thicker and darker the better. It's a pretty low-maintenance solution, and it should work.

I'm glad to hear the other tanks have been doing better.

2nd September 2009, 07:27
Unfortunately no, it is the visible front corner next to the window, but you've given me an excellent idea anyway. I can put a tall plant next to the tank and maybe a hanging plant down along its side. Maybe even a new water plant for inside the tank. (Hooray time to shop!)

Thanks so much, I am inspired!