How To Clean Fish Tank Ornaments From Algae | Aquascape Addiction

How To Clean Fish Tank Ornaments From Algae

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We cover some of the easy but effective ways of cleaning algae from your fish tank ornaments, we also look at ways to stop algae growing back to avoid the issue in the future.

How To Clean Fish Tank Ornaments From Algae

That icky green slimy stuff that grows in your aquarium is algae, something nobody wants. Algae growths can be absolutely detrimental to the health of your aquarium, plus it looks awful, and it smells really bad too.

However, algae growth is a normal part of having an aquarium. It is something that every fish owner has to deal with at one point or another. When it comes to how to clean fish tank ornaments from algae, thankfully the process is quite simple.

How To Clean Fish Tank Ornaments From Algae

As long as you follow the steps which we have outlined below, you should have no problem getting rid all of the algae on your fish tank ornaments. The process is fairly simple.

  1. Remove all of the rocks and ornaments in your fish tank which have algae growing on them.

  2. You want to take all of the aquarium ornaments and rocks and scrub the down with a brush under running hot water. Make sure that you have a small and stiff brush so that you can get all of the algae.

  3. Use the brush and make sure that you get into all of the crevices and cracks of the ornaments and rocks. You want to remove as much algae from the decorations with the brush and hot water as you can.

  4. If you cannot remove all of the algae simply by scrubbing it under hot water, you want to fill a large bucket with very hot water. You want to have a bucket big enough so you can completely submerge the ornaments and rocks.

  5. Mix some good old bleach in with the water. You will want to add quite a bit of bleach, about half a cup of it for every gallon of water in the bucket.

  6. Let all of the rocks and decorations soak in this bucket for anywhere from 15 to 60 minutes. This will help loosen all of the algae, plus it will kill off any remaining algae, thus stopping it from growing back.

  7. After you have soaked the ornaments in the bleach water, use the brush and some warm running water to scrub them down again, once again making sure to get into all of the cracks and crevices.

  8. Rinse all of the ornaments and rocks off under running cold water. Make sure to rinse them extremely well because you definitely do not want any algae getting into the fish tank. This would have disastrous consequences for all plants and fish in your aquarium.

Stopping Algae From Growing Back

Besides removing all of the algae from the rocks and decorations in your aquarium, there are also some steps that you can follow to ensure that algae does not come back with a vengeance.

Follow the tips outlined below to make sure that algae does not grow back on your ornaments.

  • Light is a big source of energy and life for algae. Depending on how much light your fish and plants need, this can be a problem. However, a good way to ensure that algae does not grow back, at least not too quickly, is to leave the aquarium lights off for at least 16 hours per day. Without a good light source, algae has a really hard time blooming.

  • If you use VHO or fluorescent light bulbs, you will want to change them every six months at the least. As these kinds of light bulbs get older and degrade, the wavelength of light which they give off changes. These changes in light wavelengths are often a big cause of algae growth.

  • Make sure that you replace around 15% to 30% of the water on a weekly basis (more on water changes here). This will help remove algae spores and particle from the water. Algae multiplies very quickly, so this is fairly important.

  • Look over your protein skimmer (if you don't have a skimmer we have reviewed some good ones here) and your filter at least once per week. An effective and well-functioning filter and protein skimmer can make a big difference in terms of keeping algae at bay. Also, the filter removes fish waste from the water, fish waste which produces ammonia, ammonia which causes algae to grow.

  • You should perform weekly tests on the water in your aquarium for things like ammonia and nitrite. Algae grows really well when there is a lot of ammonia and nitrite in the water. Testing for these substances will help you determine the problem and will help you find the right solution.

  • Cleaning your aquarium on a regular basis will help stop the algae from growing back as well. Removing uneaten food, fish waste, and any other source of contamination is key. Algae feed on all kinds of things, so having a clean tank is a great way to stop it from growing.

  • Always make sure to remove any dead fish, plants or other dead creatures from the water. They give off ammonia which algae loves feeding on.


Cleaning algae off decorations is definitely not very hard, but making sure that it does not grow in the first place can be a little tricky. However, if you follow the steps and tips outlined above, you should be able to deal with algae growth no problem.