These are my favorite methods to get pesky algae and gunk off of plastic aquarium plants. I would definitely recommend picking up a scrub brush with plastic bristles to help you clean your plants.
Unless you use bleach, youโre going to need at least some abrasion to dislodge the algae from the plastic.
You donโt need anything fancy, I like these Libman scrub brushes, but really, you can use any plastic bristle brush.
Make ABSOLUTELY sure that your scrub brush has never been used with any soaps or cleaning solutions, other than plain bleach. Cleaners can leave toxic residues, even if it seems like youโve rinsed them off. I highly recommend buying a set of unused brushes and labeling them with a permanent marker so theyโre only ever used for aquarium cleaning.
For really tiny, hard to reach spots, you can use a clean toothbrush. Just, maybe mark that too so you donโt accidentally stick it in your mouth later on. It wouldnโt actually hurt you, but it sure does sound gross.
1. Vinegar
A vinegar solution is great for cleaning up soft algaes, like green dust or brown algae.
Vinegar is fairly acidic, with a pH of between 2 and 3, which lets it break down algae and biofilm covering decor.
Itโs no match for really tough algaes, like green spot, but itโs an awesome, nontoxic cleaner for aquarium decor and equipment.
Itโs nice that you donโt have to worry about getting it on your clothes and itโs safe to use on aquarium plants with silk leaves.
To clean plastic aquarium plants with vinegar, I recommend:
- Distilled vinegar โ I usually end up getting just plain white vinegar because I buy gallon jugs of it for cleaning around my house, but you use any kind of vinegar you want.
- Tap water
- Trigger spray bottle
- Scrub brush
Method:
- Fill the spray bottle with a 50/50 mix of tap water and vinegar.
- Spray the plants down thoroughly with vinegar and let it sit for several minutes.
- Scrub with the brush and rinse. Repeat, if needed.
- Plants can be placed back in the tank immediately after rinsing with tap water. Any little traces of vinegar left on them after rinsing wonโt harm your fish.
2. Hydrogen Peroxide
Peroxide is a stronger cleaner than vinegar. It will break down tougher species, like black beard algae.
I really donโt understand why more people donโt use peroxide to clean their aquarium equipment and decor.
Just like bleach, peroxide is a powerful oxidizer that breaks down the algaeโs cell walls, making it easier to dislodge it.
But, unlike bleach, which is highly toxic to fish even in tiny amounts, peroxide is safe enough to use directly in an aquarium. Just be sure you donโt use more than 1.5 milliliters per gallon of tank water.
I have found that you need a bit more abrasion to get the algae off when you use peroxide than when you use bleach.
To clean plastic aquarium plants with peroxide, I recommend:
- 3% peroxide solution (regular drugstore peroxide is perfect)
- Trigger spray bottle
- Scrub brush
Method:
- Spray down the plants thoroughly with peroxide.
- Lightly scrub the surface with a scrub brush.
- Let the peroxide sit for a few minutes, then rinse the plants with tap water.
- Repeat the process if there are any leftover spots.
- The plastic plants can immediately go back into the tank after rinsing. Any little traces of peroxide left on them will not do any harm to your fish.
Although itโs not as powerful as bleach, peroxide could fade the colors of silk leaves. You could possibly do a test patch on a small area to see if the color will be affected.
3. Bleach
Yep, I said bleach.
But, waitโฆisnโt chlorine toxic to fish?
Why yes, yes it is.
But itโs totally safe to clean aquarium decor and equipment with a bleach solution as long as you follow these rules:
- NEVER EVER use bleach directly in the aquarium. Youโll need to soak the plants in a bucket, sink or bathtub thatโs well away from the tank. Donโt risk even a small splash of bleach solution getting into your aquarium.
- After your plants are clean, rinse them THOROUGHLY. My general rule is to rinse them until I no longer smell bleach.
- Soak plants in water with an extra dose of dechlorinator to remove any lingering traces.
I reserve this method for truly stubborn algae. Green spot algae will just straight up laugh at most algae removal methods, and so, youโll need the big guns to get it off your plastic plants.
It takes so much scrubbing and scraping to get rid of this stuff. Thereโs no way to get down into the nooks and crannies on a plastic plant to get it all off.
Submerging the plants in the bleach solution will destroy even hard to reach patches of algae.
Please, do not use bleach on plants with silk leaves. Bleach will strip all the color out of silk leaves, ruining them.
To bleach plants youโll need:
- Plain chlorine bleach
- Tap water
- Bucket large enough to submerge plants
- Dechlorinator
- Scrub brush
Make sure that you use only plain chlorine bleach, also known as sodium hypochlorite. DO NOT use things like scented bleach, โsplashlessโ bleach, color safe bleach, etc. These fancy bleaches have chemicals which are toxic to fish and can linger after rinsing and dechlorinating. You want the plain, old school, super cheap bleach.
Method:
- Mix 1 part plain bleach with 20 parts water in a bucket. For example, if you used 1 cup of bleach, youโd need to mix in 20 cups (5 quarts) of water.
- Place dirty plastic plants in the bleach solution. For really stubborn algae, let the plants soak for 15 minutes.
- Sometimes, very, very rarely, you may need to give the plants a quick scrub with a scrub brush, and then soak for another 15 minutes.
- Once the plants look nice and clean, dump the bleach solution and rinse with plain tap water until you can no longer smell bleach.
- Refill the bucket with enough tap water to cover the plants again and add a dose of dechlorinator at 5 times the normal rate. So, if you would normally add 1 ml of dechlorinator for that volume of water, youโd add 5 ml. Let the plants soak for 10-15. Dump the dechlorinator water. The plants should then be safe to go back into the tank.
I didnโt just look up this method on Google, I have used this technique dozens and dozens of times to clean decor in my own tanks. I have never lost any fish because of using this method.
Done correctly, using bleach to clean decor can really save you some labor and is the best way to sanitize aquarium equipment, in my opinion.
Conclusions
One of the nice things about plastic plants is that you can just take them out of the tank and clean them if they get covered in gunk.
Letโs face it, algae is just a part of life when you have an aquarium. Even if you do a good job of keeping it under control, it never goes away completely.
Vinegar, peroxide and bleach have been my go-to cleaners for aquarium equipment and decor for years. I especially like that peroxide is so much less toxic than bleach and it doesnโt instantly ruin your clothes if you spill it.
Most algae is no match for peroxide and scrub brush.
But sometimes, just sometimes, you run into algae thatโs tougher than a rocket fuselage. When you need to get rid of this kind of gunk, itโs time to pull out all the stops and nuke it with some bleach.
Iโve had really good luck using the techniques Iโve listed for you in this article. You can also use these same methods to clean things like rocks and resin decor. I especially like peroxide for resin pieces.
I hope you find this article helpful.
I wish you and your fish the very best!

Oh thank you for this!! I have tried and tried to get plants clean. The bleach method is a game changer. My aquarium looks so much better with clean plants.
Thanks Katherine! Just what I wanted to know.