How do you get rid of algae in the fish tank?

Question

We have a problem in our tank. There is algae that we can't seem to get rid of. My husband believes that it is living mostly in the filter and would like to know what the best water temperature to clean the fliter out would be, or if that would even help.

Also, can you recommend a permenant solution? We have a 55 gallon tank with 5 oscars, 2 kissing fish and 2 pletcos. We are using 2-40 gallon filters.

Just to let you know, the algae isn't growing on the sides of the tank, it's surviving in the water.

We have 2 pletco's which are algae eaters and we have the drops. They aren't working. We also clean the tank once a week, any more then that and the fish may die.

Thanks for the answers. We are trying to find someone to take the oscars off our hands. We were kinda lied to about the oscars when we got them. The fish store never told us that they would be so disgusting, they also said that these fish would be friendly with other fish. Imagine our surprise when we realized why our other fish were dying off. Once we get rid of the oscars, we will get the tank back in order.

Answer 1

By "living in the water" I'm assumung your water is actually green - this is a free-floating one-celled algae that sometimes gets into tanks and it can become a problem making your water look like pea soup. This isn't something algae eaters (like plecos or snails) can remove.

A few things you might try. First, if you don't have any live aquatic plants in the tank, turn the lights off. Algae uses photosynthesis to make food for itself, so without light, you remove it's ability to make food.

Second, manage nutrients in the tank. You have a lot of fish that have big appetites and messy eating habits (and won't be able to be kept in a 55 forever). They produce a LOT of wastes, and these get converted to nitrate (a plant and algae fertilizer) by bacteria in the tank. The only way to remove the nitrate is to use live plants (which your plecos will consider a salad buffet) or to do frequent partial water changes to remove physically. If you test your water, the nitrate should read under 40 ppm (too high of levels are harmful to your fish as well, although nitrate needs to be in much higher concentrations than ammonia or nitrite to be fatal). There's also a possibility that you're getting nitrate in your water supply, so you're adding it when you do water changes, so it's worth it to have your tap water tested as well. You might need to use reverse osmosis water, or a resin that's made to remove nitrate to remove this. Also, see if you can get test results from your water company to see if they add phosphate (another plant and algae fertilizer) to the water supply (another resin can remove this).

Another possible option is to add a diatom filter to your system - this can remove the algae physically, but won't change the nitrates if these are a problem.

Answer 2

Is your algae green? If yes, it's not harmful. Algae needs two things to thrive: Light and nutrients. Light, direct or indirect, from a window or from leaving tank lights on too long will promote algae. Tank lights only need to be on 4-6 hours per day. Nutrients are provided by way of nitrates in the tank. Levels of nitrates exceeding 20ppm and excessive light will produce green algae.

Your 55 gallon tank is overstocked, by the way. The oscars will each need about 50 gallons of water per adult fish. The 2 gourami need about 40 gallons each-minimum and some plecos can reach 20". The filtration isn't the main problem with the 55 gallon tank, rather it's the potential adult size of the fish and territorial needs.

A permanent algae solution would be to reduce the amount of light to your tank and add several live plants (will use up some nitrate and provide cover for the gourami) Testing for ammonia, nitrite and nitrates will let you know how your biological filter is doing. Ammonia and nitrite should be 0ppm and nitrates should be 20ppm or less. Perform partial water changes as necessary to get your parameters in line.

And, no, the algae isn't coming from the filter.

If the algae is brown, it's generally produced as a tank completes the nitrogen cycle. With limited light and water changes it will go away.

Answer 3

Well first off you have way too many fish in the tank, A single Oscar needs 55 gallon minimum with no tank mates. Plecos need a 55 - 75 gallon pretty much to themselves because they can get 18 - 24 inches. The kissing fish sound like kissing gouramis and they get to be 12 inches each. You have far to many fish in the tank, put it this way, the fish you have in that tank should be in a 300+ gallon tank. All extra fish then it might be causing the algae. Also keep the light off most of the time.

Answer 4

I feel your best first step is to take a sample of the algae to an aquarium to identify it. The growth may be beneficial to your fish.

I work on if temperature is likely to kill something it is likely to be too hot for many plastics but go with boiling water if you are sure the plastic can handle it then give the plastic time to get back to normal temperature the ice water o some time in the freezer.

You may find that when taking the sample to the aquarium that they will have a solution to kill the algae. I am a big one for more natural methods like use vinegar to wash the tank and filter (with the fish having a holiday in another container) and rinse all really well.

Or by snails, bottom feeding fish etc.

Answer 5

A small amount of algae is healthy and normal but too much can be bad news. You can never get rid of algae completely but you can reduce it to where it can't be seen. I'd suggest exposing the tank to less light, (is the tank near a window or do you have the tank light on too much?), and doing lots of water changes and scrubbing the algae colonies off the walls, the more the better anyway. Cleaning the filter won't help much cause the algae is always present so might as well focus on keeping the levels low in the tank by cleaning. good luck :)

Answer 6

well first of all if the tank is in the sun you will have to move it. The sunlight causes the algae to grow or turn the light off during the day and late at night. Snails work great along with algae eaters for getting rid of it.

Answer 7

It sounds like you have plenty of filtering power.

You can clean out your filters with hot tap water - no soap. Sometimes there's a lot of scum hiding down in them which contributes to the nitrate load in the tank.

It's the excess nitrates and light that contribute to an algae overgrowth. So in order to turn your water clear, you need to reduce the light and reduce the nitrates.

If your tank is by a window, the shade needs to stay closed. Keep your tank's overhead light on for no more than 6 hours a day, until your algae is under control. And check your nitrate level. It needs to stay under 40 ppm.

You have a huge bio-overload in your tank with 5 oscars, 2 gouramis and 2 plecos. These guys are all eating and pooping machines. And all that waste adds to more nitrates which algae loves!!!

Eventually you will have to either get a bigger tank, or sell some of your fish. In the meantime, you may have to do daily 10% water changes until your water turns clear.

Please check your replacement water for nitrates. Maybe your water source is high in nitrates or phosphates and is contributing to your problem.

Answer 8

take the filters off and take the filter part out and wash with a bleach solution. rinse off very well and put it back together. the two ways to get rid of the algae is to feed the fish properly and get some algae eaters for the type of container and water

Answer 9

I hope your algae isn't black. I have experienced this. If your algae is green, there usually is no perminant solution. Your algae eaters are doing their job. Scrape the sides of your tank with some sort of credit card or membership card. If you have plastic plants or fake logs, try bleaching them and scrubbing well. Make sure you rinse them before putting them back in. If this is an annoying and persistent problem, consult your local pet store. There are sometimes different drops you can put in the take that will solve the problem. Good luck!

Answer 10

The oscars that you have is the problem.I use to have them and they can be very nasty fish. The temp.should be below the green in 65 area.You can also try Algie Destroyer advanced. I love fish tanks and I have two 29 gallions.Tropical and butterfly gold fish.
Also on the algie no sun light.