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Avoid Becoming an Algae Farmer

PostPosted: Sat Nov 29, 2008 6:33 pm
by Crazygar
Avoid becoming an Algae Farmer

Steps for doing battle aganist algae when it does appear.

It seems to me that in order to understand and control algae you need to first adopt a healthy livable philosophy about algae in a planted tank. I'll share my thoughts and views on the subject and you can decide if anything makes logical sense to you the reader.

Algae comes to every tank, it is unavoidable. The issue is in how well it's controlled and whether it becomes a visible nuisance. I like to relate algae in an aquarium to weeds in an outdoor garden. If after planting your garden you failed to provide food and water for your neat rows of plants what would happen? Weeds would appear and begin to flourish. Even if you water and feed the plants, unless you stay vigilant on maintenance issues you will still encounter nuisance amounts of weeds. The weeds will rob much needed light, food, and water from your garden plants. Algae is like those garden weeds. If you don't provide the plants what they need in regards to light, nutrients, and CO2 they will succumb to an infestation of weeds...err algae. Two issues seem to be very apparent regarding algae in a planted tank. The first, algae is always present. The best you can hope for is to control it so that it looks natural and not distracting from your aquascape and robbing the health of the plants. The second is that algae control is related to giving the plants everything they need regarding lighting, nutrients, and CO2. If you limit any nutrient including CO2 you will be fostering an environment that weeds...err algae will be able to gain the upper hand.

So let's enter into this with the understanding that algae is always present in a healthy thriving planted tank. Let's also be clear that in a healthy thriving planted tank that to spot this algae requires more than a glance. To find and see algae in a healthy thriving planted tank requires carefully looking throughout the plants and tank. Can you or do you want to eliminate every trace of algae? Personally I don't think it's possible, at least not for any length of time. One could bleach all the plants and decorations and have a completely algae free tank for a while I suppose. Too sterile and unnatural for my tastes. The best approach in my opinion is to recognize that algae is part of the tank just like weeds are part of the garden.

Now you have a good idea of my personal philosophy on algae in planted tanks. This page would be less than helpful though if I did not also address how to combat algae when it does get out of control. I'll separate algae into main groups and give multiple options where they exist.

BGA/Blue Green Algae/Cyanobacteria
This is actually an organism that is more closely related to bacteria than algae but we always lump it into algae for ease of discussion. BGA has many species and forms and causes great angst among planted tank beginners and experienced hobbyist alike. Some forms of BGA grow slow and are very difficult to kill, other species grow very quickly and can overwhelm and "smother" all the plants in short order. I have encountered some especially virulent species that wouldn't die without treating the tank with antibiotics.

Treatment Option 1:
Tank blackout. This method is very effective against most species of BGA. Manually remove as much of the slimy BGA as possible. Then do a large (50-70%) water change and cover the tank with trash bags or thick blankets for 3-4 days. No light whatsoever should enter the tank. Your fish and plants will be fine, some plants like Glossostigma may get a bit "leggy" but you can give it a "haircut" and it will return to proper form in short order. Upon removal of the trash bags/blankets do another 50-70% water change, this helps get rid of all the dead BGA. Dose 10 ppm of nitrate and maintain nitrate at 5-20 ppm throughout the week.

Treatment Option 2:
Many times if the BGA is located in just one spot in the tank you can redirect the water current to kill the BGA. Stagnate spots are prime areas for BGA to develop. Generally speaking BGA doesn't like heavy current. I have positioned a power head directed into a patch of BGA and caused it to shrink and even disappear within days. Insuring that water circulation is ample in a planted tank helps thwart BGA outbreaks. Dose 10 ppm of nitrate and maintain nitrate at 5-20 ppm throughout the week.

Treatment Option 3:
Sometimes aquarists will inadvertently allow nitrate to drop to zero and remain there for several days to even weeks on end. When plants are nitrogen starved the environment is ripe for a BGA infestation. Increasing current and adding nitrate via potassium nitrate additions can often times eliminate BGA under these circumstances, so dose 10 ppm of nitrate and maintain nitrate at 5-20 ppm throughout the week.

Treatment Option 4:
Some species of BGA are extremely virulent. Repeated changes in current, blackouts, nitrate additions, low yield nuclear weapons...nothing is able to fully beat back the BGA. In these extreme cases it may be necessary to, as a last resort, use an antibiotic such as erythromycin to kill the bacteria. I have had success with Maracyn. Dose at the full rate of 200mg per 10 gallons of water per day and dose for the full five days. Treatment with lower doses or shorter times can lead to not fully killing the bacteria and "could" lead to a more resistant strain. Like the use of any medication this should only be considered after repeated other methods fail. Do a 50-70% water change after the full treatment and dose 10 ppm of nitrate and maintain nitrate at 5-20 ppm throughout the week.

BBA/Black Brush Algae/Black Beard Algae

Personally this is the most objectionable looking algae to me. Controlling BBA is fairly straightforward thankfully. Make sure that under moderate to high light conditions that CO2 is in a range of 15-30ppm. Fluctuating CO2 levels as found with DIY yeast injection seem to be more likely to cause an outbreak of BBA. As with any algae problem, insure that nitrate, phosphates, iron, and traces are being dosed in large enough amounts so that you are certain that their levels fall within the specified ranges given on the "Nutrients/Fertilizer" web page at this link
Lastly, the best control is the use of an algae eating team of experts. Siamese Algae Eaters (SAE) are very good at keeping this algae in check. I have also noticed some individual Rosy Barbs will snack upon BBA too. In severe infestations you will need to manually remove affected leaves and/or plants. The algae is stuck to the plant with such tenacity that manual removal usually causes too much tissue damage to the leaves...unless you are a SAE.

Brown/Diatom Algae
Except at startup this is not an algae that should be visible in a healthy planted tank. Otos or Otocinclus affinis are excellent little fish that will remove and keep this algae in check in a planted tank. I like to use one Oto per sq. ft. of tank bottom.

Green Dust Algae
This is that dusty looking algae that coats the front and side glass. It's generally a good sign if that's the only algae that is noticeable in your tank. A quick scraping of the glass prior to your water change is all that's needed to control this non nuisance algae.

Thread/Hair Algae

My views based on my circumstances. It's been my experience that if I have too much iron in my tank that this is the algae most likely to become a problem. Most Thread/Hair algaes grow extremely fast. You can manually remove handfuls every couple of days. While it's likely that excess iron by itself isn't a problem, if excess iron is combined with high levels of dissolved organics and/or other nutrient levels out of balance, then Hair/Thread algae is extremely likely. So, the approach to eliminating Hair/Thread algae is fairly straightforward too. Manually removed as much algae as possible. Do a 50-70% water change. Dose nitrate, phosphate, and traces to the needed amounts. Insure that CO2 is in the 15-30ppm range...consistently. Repeat the manual removal, water change, and redosing of nutrients on a weekly basis. Adding an algae eating crew will help eliminate and keep this algae in check. Personally I have great success with SAE's, Rosy Barbs, American-Flag Fish, Amano Shrimp, and Bristlenose Plecos.

Green Spot Algae

These are hard circular algae spots that take hard scrubbing too remove from the tank glass. It's been my experience that moderate to high light phosphate limited tanks have more problems with green spot algae on plants. A plant expert from online forms, 2la (Tula Top) suggests using Rubbernose Plecos. My limited use has shown they are excellent at reducing green spot algae on plants, but that they are very tenacious raspers and may cause some tissue damage on leaves, like Anubias that remain in the tank for long periods being rasped on constantly. If you have issues with Green Spot the Rubbernose Pleco is certainly worth a try in your tank. Green Spot Algae is often eliminated with increasing phosphate levels in your water. Try to maintain at least 0.3 to 0.5 of phosphates throughout the week.

Hopefully you gained something from reading my experiences and views. Please understand that I make no claim of being an expert with all the answers. Others may have completely different experiences and you should always seek out alternative points of view.