How to Clean Aquarium Glass – Residue and Algae

How to Clean Aquarium Glass
How to Clean Aquarium Glass, photo by AdamG

Learning how to clean aquarium glass is easier than you think. You don’t need to spend a lot of money to do it or spend a lot of time scraping your tank with a brush and water like most inexperienced fish-keepers will do. The best way to clean aquarium glass is by knowing what your problem is (residue or algae) and by attacking it the right away.

How to Clean Aquarium Glass Residue

If what you have looks like white residue, it is most likely lime buildup. Lime buildup occurs from mineral and calcium build up. When your water level starts to decrease and evaporate, the minerals are left behind, getting stuck to the top of the glass walls, leaving behind the white residue that you want to get off. The below methods will help you get that nasty and ugly-looking residue off the glass.

1. Vinegar

Grab a spray bottle and fill it with white vinegar, then spray the aquarium glass down. Let it sit for about 1o minutes and start scrubbing. You might have to do this 2 – 3 times to get all the residue off. For best results, lay the tank down on its side and pour vinegar into the tank so it submerges the side glass. This will penetrate the residue extremely well.

2. Razor Blades

Razor blades do a pretty good job scrapping off residue that doesn’t want to come off. If there is a deposit left behind after the razor blade, it is most likely etching. This is where the glass surface has been eaten away by organic acids or other reactive chemicals.

3. Bleach & Water Solution

Bleach is a very strong chemical which should only be used for fish tanks that are not going to be used any time soon. You will need to wash, dry, and repeat several times when using bleach to allow all bleach chemicals to leave the tank. Any bleach chemical substance left behind will kill your fish. For proper use, use a 1 part bleach and 9 parts water  solution (ex: 1 cup bleach and 9 cups water). Never exceed the limit of 10% bleach and never soak an aquarium for more than 15 minutes with bleach.


You can either fill the tank up with 90% water and 10% bleach and let it sit for 15 minutes, or take a spray bottle with the same percentages of water and bleach, and spray the fish tank down. After 15 minutes, fill the tank up with clear water, drain it out and let the fish tank air try. Once it dries, repeat the process once more. If you still smell bleach afterwards, repeat the process one last time.

How to Clean Algae From Fish Tank

Algae is no joke (any fish-keeper will tell you that). Algae can honestly destroy your tank if not maintained or controlled properly. Below are a few ways you can easily get rid of algae from a fish tank.

1. Feed Fish Appropriately

Overfeeding your fish can be a real problem for algae. Algae grows on left over food items and fish waste. This doesn’t mean to feed your fish small amounts. It just means to feed your fish sparingly, enough to fill them up, but not enough to allow left-over food to linger around. This will just help algae grow.

2. Control the Lights

Lights should be turned on only about 8 – 12 hours a day. Anything more than that will encourage algae growth. If you have live plants, allow for 10 – 12 hours of lighting throughout the day. If you only have fake plants and ornaments, try to stay between 8 – 10 hours of lighting a day.

3. Frequent Water Changes

Water changes help remove excess nutrients and nitrate (which helps algae growth) from the water. If you are changing the water weekly, you should stick to a 10% water change. If you are changing the water monthly, you should stick to a 30% water change.

4. Test Tap Water

Most of us use our own water at home for water changes, which may sometimes be the problem for algae growth. If your tap water has high levels of phosphate in it, it may be aiding in algae growth. Testing your water changes can help you reassure your tap water is good to use.

5. Include Live Plants

Live plants help take away nutrients algae needs to grow. Because live plants feed on similar items as algae, the live plants will deprive the algae from a food source.

6. Change Filter Media

Sometimes algae can be caused by bad filter media or old filter media. If your filter media is old, replace it. If it’s not doing a good job, replace the media with something better. Bad filter media can increase phosphate levels which will surely increase algae growth. You should stick with a good chemical removal media.

7. Get Algae Eater Fish & Invertebrates

Algae eaters will help with the fight against algae. Bristlenose plecos, ghost shrimp, siamese algae eater, nerite snails, and malaysian trumpet snails are great algae eaters. They still need a special fish diet, but they surely will help eat some of the algae lingering around the tank.

Tips for Cleaning Aquarium Glass

  • Do not use the corner of knives, box cutters, or scrapers. Corners will scratch up the glass.
  • Do not put any fish into the tank without cleaning the tank thoroughly.
  • Stay away from using any tools near the seals. Some tools can scrape and take off the aquarium seals.
  • Use caution when using chemicals and tools. Wear protective eye wear and gloves.
  • If using store-bought chemicals, read directions carefully. I have heard story’s about fish-keepers wiping their entire tank out from misusing an aquarium cleaning product.

Now you should know how to clean aquarium glass effectively and correctly.

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