Restoring A Fish Tank To Its Inner And Outer Glory

[catfish4ever]

Got a fifty Gallon...
 
It has quite a few hardwater stains on the tank, i would like to remove these stains.
 
I have tried White Vinegar but it dosent quite cut it.
 
Pleaasse help

 

[daizeUK]

I use a razor blade to remove tough limescale, or other kind of hard scraping tool.  I've never had problems scratching the glass by doing this but best be careful.

 

[nofishinginmytank]

You could try warm water with lemon juice, I know that it works for getting grubby finger prints off windows

 

[TwoTankAmin]

I have always used muriatic acid. But you need to know what you are doing as the stuff will burn. I use it diluted. It is a two step process and I suggest wearing rubber gloves.
 
1. The tank is filled and a weak acid solution is created by adding the acid to the water already in the tank during filling. The filling will mix the acid.
2. After being allowed to sit for about 15 minutes, the tank is drained. This will have removesdall but the most stubborn spots.
3. In a small container mix a stronger solution of acid and water. Use an old piece of towel or washcloth (and for sure wearing rubber gloves) dip the cloth into the solution and then press the "rag" against each remaining calcium deposit and hold it there for a bit. At this stage it should scrape right off with ease using an algae scraper or single edge razor blade.
4. Rinse out the tank so no acid water is left in it.
 
I would add that this removal is one of the two things I do with a new used tank. The second process is to sterilize it and use a bleach solution which is allowed to sit in the tank for about 30 minutes. Again the tank whoul be well rinsed from this and then allowed to dry completely before you get to the fun part.

 

[malfunction]

Does the tank currently have any livestock in it? If not, you could try methylated spirits - I found it very effective at cleaning hard water marks on my latest tank.