# How to get "scum" off old aquarium



## LisaLB24

Hi, all. I'm looking at purchasing a 150 gal tank from craigslist for a steal. It looks like it wasn't cleaned very thouroughly before being broken down so there is a white scummy residue all over the inside. Will I be able to clean it off? What's the best way to approach this stuff?


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## Tazman

Vinegar will work if it is just calcium deposits from hard water.

Use a piece of toliet paper or kitchen roll soaked in vinegar and left on the area that is being stubborn. Gently with a razor blade (if needed) scrap the residue off.

Do not do this if the tank is acrylic.


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## LisaLB24

Thanks, I was just hoping it's not something permanent!


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## Tazman

Try the vinegar and you will probably find a lot will come off straight away.

If you have to use a razor blade for very stubborn areas, please take extra care and do it slowly...otherwise you will scratch the glass.

Soaking with vinegar soaked paper towel for a short time will 99.9% work though.

Once it is all off, clean the tank with water, NO SOAP or chemicals and let it air dry...that way any vinegar left over will gas off.


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## Geomancer

Yeah, usually people use a 50/50 vinegar water solution to clean aquarium glass.

Acrylic can scratch very easily, hopefully it is glass!


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## LisaLB24

It is glass so hopefully the vinegar and rzor blade will work!


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## Deadstroke174

How will vinegar work on plastic? I bought an old tank from someone and it has some calcium deposites on the plastic filter and hoods


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## Tazman

Soaking them will be fine, just make sure to clean then thoroughly once you are done.

Vinegar can be used on most plastics except acrylic!


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## redchigh

Some older drug stores sell boric acid in a powder form. You can add 1/2 tsp per gallon to the water and just fill the tank with it.. You can also use a product called 'Ph Down' mixed as per instructions and let the tank soak. (rinse well before you add fish though! Trace amounts will not harm the fish, but rinse well to be on the safe side.)


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