Controlling Brush Algae (Part 2)

Introduction notes: This is a follow-up article to Brush Algae, Not Hair Algae. Click on any images in this article to expand. I conclude this article with Flourish Excel as the most effective product I tried for controlling brush algae in my aquariums. The rest of this long post will show that I experimented with a variety of other things first. Please keep in mind I'm a hobbyist. I'm not a scientist. Results may not be the same in your aquariums. Hopefully, my observations will be useful to others who grapple with brush algae.

(Picture above shows my 20 gallon wide earlier on, prior to the appearance of brush algae.)

Background: My aquariums became a favorite breeding ground for brush algae over time. Brush is a slow growing black, sometimes grayish or greenish furry tuft-like substance that likes to anchor itself on the rim of leaves, substrate and other hardware in the tank.

As time passed, the amount of brush increased. The growth also seemingly sped up. Eventually, this black fur covered much of the new plant foliage.

I do not know or understand how pests enter aquariums. I assume they come from varied sources. For instance, I take it for granted new plants often introduce unwanted pests that tag along. My main focus as a hobbyist, is to find a way to recover from and control whatever disaster comes.

(Picture on left shows grasses and substrate with brush algae. This was the beginning stages of the brush algae infestation.)

Finding the Cause: There's a line of thinking in the planted aquarium hobby that suggests it's better to find the source of the problem and correct it rather than to mask it with an additive. In other words, some are saying that such problems as with brush algae is caused by an unbalance in the aquarium. To that, I reply: Ok. I'll keep that in mind. It's a great ideal, and a logical starting point. However, I may never reach anywhere near ecological perfection in my planted aquariums. Anyway, I need to solve my current brush problem.

Regardless of unbalance or what-not, my goal is to reverse the effects and keep the problem under control, if not eliminate it altogether. If that involves using an additive, or changing the tank's parameters, I really don't care as long as the result can be reproduced time and time again without re-building the aquarium from scratch. I want a healthy aquarium for both fish and plants. If using an additive is a form of cheating, then fine. I cheat sometimes.

On that quest, I end up reading, testing, sharing with others and experimenting. Ideally, I would find the root cause of the problem and make necessary changes. In the case of brush algae, I have had very little success finding out what makes it so tenacious, but I have at last, found a way to reduce it to a minimum using Flourish Excel.

Failed Attempts: The first suggestion made to me was to reduce iron. According to some, it was imperative that I reduce or starve the aquarium of this fertilizer and that it was the root cause of the healthy brush. Therefore, before anything else, I stopped dosing PPS-Pro, which was the most concentrated source of iron. This did not even have the slightest improvement effect on the aquarium. The brush was just as energetic as before.

(Picture above shows progression. The brush is now growing on the rims of sword leaves as well as on the substrate where it can find light. It also continues to cover new grass growth.)

Iron may be difficult to control in my aquariums because I use potting soil. I assume there's always some iron leeching from soil substrates. If iron is such a catalyst for brush algae, it might explain why it likes to grow on substrate in those areas where light penetrates. The combination of an iron-rich substrate and light might explain that. I also noticed that Cabomba carolinia never gets brush algae. This plant requires much iron. Could it be that the plant takes up so much iron that it doesn't allow the brush to grow  on it? Or is it just the plant's rapid and short life cycle? It does appear that brush grows faster on some plants than others. Hygrophilla difformis or Water Wysteria is another one that never seems affected by brush in my tanks.

Logically then, if brush needs iron, the reduction of iron should have a negative effect on brush growth. It's possible, but I would have to be able to measure this. (As if I was going to count brush filaments every day...) At any rate, from the above experiment, brush algae survived quite well with less or little iron.

Light: I then let Duckweed, Water Lettuce and the like take over the surface of the aquarium. I let the tank sit for weeks, without liquid fertilizers or much light. Some harm came to the plants as they were starved for light, but the brush algae continued its takeover, unabated.

(Picture here shows an overgrowth of floating plants. The most prominent is Water Lettuce. It's actually quite pretty but prevents light from reaching plants down below.)

So, iron reduction and light reduction over two months did not reverse the brush algae problem. It is hard to measure if the brush stopped growing or even slowed down, but it was clear that it had not receded. One indicator is that new plant growth invariably became covered with brush.

Copper: Enter the more drastic approaches. I dosed one aquarium with Had-a-Snail, a product that contains Copper Sulfate Pentahydrate. I continued the treatment for several days but did not see an improvement.

Hydrogen Peroxide: I read success stories online where hobbyists used syringes to spot-treat infested plants with Hydrogen peroxide. I thought this to be great news. Seeking a lasting treatment that doesn't bring harm to plants and fish however, I was hesitant to drop H.P. in my tanks. Both Copper and Hydrogen peroxide are potentially hazardous to the fish and perhaps some plants.

(Photo on left shows pieces of Kleiner Bar Sword infested with brush algae. Jar on right was treated with 3% solution of Hydrogen peroxide, with no visible improvement after 24 hours.)

Nevertheless, I purchased a bottle and proceeded to experiment. Not wanting to put this solution in the aquarium, I cut leaves off a Kleiner Bar Sword and placed them in two separate small jars with RO water. The first jar served as a control for comparison, and was not treated. I added a many drops of H.P. in the second jar. Come next morning, both jars looked the same, with no improvement in the one that had received a treatment. I was expecting the brush to change color overnight. I added more Hydrogen peroxide and waited another 24 hours, again, no difference. I assume the solution may have been too weak.

CO2: Some are of the opinion that CO2 injection will alleviate or control brush algae. All of my aquariums receive injected CO2 from DIY yeast cannisters. The CO2 levels are always maintained because I alternat cannisters on a weekly basis. The mixture is thoroughly dissolved with Red Sea CO2 Reactor 500. Seen here on left. (Click link to read my first review of this product.) In other words, all my aquariums receive CO2 gas in relatively large quantities, which has dramatically improved plant growth. Nevertheless, it has not stopped the progression of brush algae.

Algaecide: I have also been using AlgaeFix as directed, which is safe for plants, and Barley straw extract as directed. I use these products as part of my aquarium maintenance procedures. They also have had no observed effect on brush algae. Perhaps they help in slowing it down, but since I have been using these products from the start, I have not been able to measure this.

I also tried a couple of products that claim to be able to kill blue-green algae. One such product was called UltraLife Blue-green Algae Remover. It was ineffective against brush algae.

Aquarium Parameters: I have four small aquariums of various size now, ranging from 35 gallons to 10 gallons. All my aquariums have a soil, flint, clay and gravel substrate. The largest tank also has 50% EcoComplete. I use Reverse Osmosis water only. I fertilize with PPS-Pro Poor Man's Drops only. My fixtures are home made jetting very bright light on the water ten hours a day. CO2 is injected in all tanks. All aquariums receive a large water change weekly. All but the smallest aquarium have brush. This tank has no algae at all. Likewise, it has no fish, only a few slow-growing sword plants.

Success: Finally, I tried a product called Flourish Excel. This is liquid organic carbon compound of some sort that bloggers say relieves brush algae. I have to concur. It is the only product that has shown marked improvement in the control of this tenacious brush algae. This is a long article for a few sentences to praise Excel, I know. But I wanted to show that I had also tried other things first.

I started overdosing the 20 gallon wide with Flourish in conjunction with the other previous treatments. The tank I've pictured throughout the article received Blue-Green Algae Remover as directed, Copper sulfate in daily small doses, as well as 30ml or Flourish Excel every day. Within days, the brush algae turned red. This was a significant change.

A time later, the fish started to nibble the brush away. They ate it directly off plants and substrate. It seems the treatment was making it less hardy. Somehow, the fish were finding it palatable. I took a video of fish eating Brush, and will post it to my blog soon.

A time later, the brush started lifting off the substrate. Tufts of brush started filling the filter intake. I interpreted this as a sign that it could no longer anchor itself properly. I was overjoyed. I continued the treatment.

A word of caution: 30 ml Excel in a 20 gallon aquarium is way more than directed. This is an overdose. It did not bring harm to fish, nor plants. However, I noticed that when mixed with AlgaeFix, fish became lethargic. I stock mostly Platies. Other fish may be much more sensitive to an overdose of Excel. Test accordingly.

(Picture above shows brush algae turned red after being treated with an overdose of Flourish Excel.)

Currently, the aquarium has a lot of mulm hovering where brush used to grow. Small creeping plants such as Four Leaf Clover and grasses are slowly re-taking the bottom where light is available. The brush growth has clearly fallen as it no longer covers new plant growth. New sword leaves are free and clear of brush.

(Picture on left shows 20 gallon wide as of this morning. Brush still exists near the bottom, but it no longer overtakes plants. I continue to treat it with Flourish Excel)

As far as my other aquariums are concerned, the large tank still has brush, but less than originally. The other 20 gallon aquarium has no brush algae to speak of. The only main ingredient in the fight against brush that was common to all three aquariums is the Flourish. As a matter of fact, the 20 gallon that did not receive Copper or Blue-Green Algae Remover is the one showing the most improvement. I've resumed regular PPS-Pro fertilizing in all three aquariums.

Comments

[MIKE ANDERSON]

really liked your brush algie article.did you just keep adding the Flourish or do water changes too,and if so what%?i have a 180 gal.community tank with this problem..thanks and cheers Mike

[Tim]

Do NOT add this stuff if you have young Discus... it killed both of mine within hours.

[Marc]

Thanks Mike. I kept adding Flourish on a daily basis and did water changes as needed.