Newbie - Hazed appearance to used aquarium

[Sun Bunny]

Hello.....I am a new member, thank you for adding me. I have just purchased a used aquarium at a garage sale. It appears to be in good shape and I filled it with water as soon as I got it home to verify it doesn't leak. However, the inside glass is very hazy near bottom. The hazy section is approximately 5 inches wide and is goes around the tank (like a ring around a tub). I can't feel any difference between the clear glass above and below the haze, but it is unsightly. I contacted the seller and he said the tank sat MOSTLY empty for approximately 9 years with the water and all the decorations in the tank. (?) Now I am trying to come up with a way to clean off the haze so it doesn't obstruct the view of my new fish. Any help and suggestions would be wonderful!

 

[Aiken Drum]

Is the aquarium glass or acrylic? Glass aquariums are separate pieces of glass "glued" together with silicone sealant. Acrylic aquariums are "welded" to form a solid unit with no joints.

Can you post a photo of this haze and one of the joints?

 

[Sun Bunny]

 

[Sun Bunny]

This is a picture of the side of the tank. You can see the glass is clear at the very bottom (about 1 1/2 to 2 inches and then above the haze as well. Not sure I mentioned it, but this is a 100 gallon tank, so not easily moved. Pretty obvious it had a leak at one time...but since I will be using it as a terrarium....it shouldn't be a problem. Thanks for asking. It is a glass tank.

 

[Aiken Drum]

It looks like a hard water stain. This is caused when water evaporates and leaves behind a calcium deposit on the glass. Similar to limescale build up inside kettles thats common in areas with hard water supplies. This would be consistent with a 9 year old aquarium thats just been left with water in it.

Acid should clear this up and disolve the calcium deposit. Mix white vinegar 50/50 with water in a spray bottle. Lay the aquarium on its side and liberally spray the affected area and leave for 20 minutes. Then scrub with a non abrasive cloth. Repeat on all affected sides. Particularly stubborn areas may need scraping with a razor blade. Thoroughly rinse with warm water afterwards.

I have occasionally heard of particularly ingrained stains not being able to clear. This aquarium has been sat for 9 years. There are also bespoke chemical products to clear hard water stains. Ive heard of a product called Bar Keepers Friend that has treated particularly stubborn stains.

 

[Airborne 82nd]

I've used this with good luck. let it soak for 30 min. Get a razor blade and have fun.

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