Best way to clean residue off old glass tanks?

landmineyouth

Gambusia
MFK Member
Sep 3, 2005
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North Miami
www.djrobriggs.com
Hey guys. I am about to set up a used 300 gallon glass tank, but the inside glass has a strange multi-colored film on it. It does not look as noticable when the tank is filled with water, but I would still like to remove it before stocking the tank.

I also figured since the tank is currently unstocked and unfilled, I could use a potentially harsher chemical to do so, such as bleach perhaps. The problem here is knowing HOW MUCH to use (ie- how many gallons of chemical X + gallons of water).

Anyone have any tips?
 

skjl47

Goliath Tigerfish
MFK Member
May 16, 2011
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Hello; I have made a paste by adding a little water to salt. This salt paste does not scratch glass and will remove a lot of the stuff on the glass surfaces. I use table salt without iodine. I also have learned to be very careful about bits of grit, gravel and such getting into the paste as this will scratch the tank. I also use a soft sponge or cloth that will not scratch the glass on it's own. Wetting the surface before trying to clean it helps loosen the deposits.

Some stubborn deposits require a different approach. I have not used bleach so cannot comment from experience, but feel that it may more of a disinfectant thana cleaner. Vinegar should soften mineral deposits . Perhaps a vinegar solution in a spray bottle and a non abrasive sponge. I am not sure how much vinegar in a full tank would be effective, but even a weak solution should soften mineral deposits given enough time. we are talking about a tank that will be rinsed out before adding fish

I have often used razor blade scrapers to remove stubborn deposits. I find that this works well if used with care. The blades need to be new and held at a very shallow angle. I have several blades and replace them often. The corners of the blades can be tweaked and will scratch fine lines on the glass, so I try to not bang the corners into things. Again wetting the deposits seems to help some.
 

Dan F

Fire Eel
MFK Member
Dec 10, 2007
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I have had good luck with vinegar and the "non-scratching" (blue) Scotch-Brite pad. For really stubborn deposits I will lay vinegar-soaked paper towels on the problem areas for a while and then scrub them off once softened.
 

scrup

Jack Dempsey
MFK Member
Feb 17, 2010
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Boulder
I use razor blades. Just keep them at an angle and you will reduce the chance of scratching. I've only scratched a tank once with a razor, and this was just me being careless and exhausted after removing a fully siliconed 150lb concrete background from a tank.

I use this kind- http://www.milko-blade.com/bladeimages/MKB-03-5.gif

Just hold it in my hand and keep it at a sharp angle. Only time I had to use a little vinegar was on some really stubborn and thick calcium deposits. Let it soak then hit it with a razor.

I have cut myself once or twice when I lost my grip, usually after an hour or so of scraping when I start to get cramps (Damn carpal tunnel).
 

Mille473

Feeder Fish
MFK Member
Oct 5, 2011
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N. Indiana
Vinegar for sure. Safe and very effective. Don't use bleach. I use about half a gallon vinegar when cleaning my 100 gallon and a whole lot of water. Add the vinegar to the tank, then scrub. You can use a lot of different things to scrub with, I even used Iron wool once without scratches :headbang2!!! Scrub until you get everything off then rinse like heck, pretty much until you can't smell vinegar anymore. Then, in your case, I'd go back with a razor blade to get any small areas. If it is reallyyyyy bad you can soak the tank with a few gallons of vinegar and mix with water, then scrub.

Hope that helps!
 

landmineyouth

Gambusia
MFK Member
Sep 3, 2005
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North Miami
www.djrobriggs.com
Hey guys, already soaked the tank in 5 gallons of white vinegar / 295 gallons of water. It did not take the discoloration off the glass, I suppose scraping with a razor blade is my best option, although seems very time consuming and also tricky, as the tank is very tall and getting to all the areas at the right angle could take a long time.

The tank itself is already very scratched so Im not worried about damaging it any more..
 

WckedMidas

Fire Eel
MFK Member
Mar 31, 2005
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BODYMORE MD
forgot what i wanted to say
 
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