Hard Water Stains on glass

[aedile]

I have hard water stains (or calcium build up or lime build up) on an old tank that I am wanting to refurbish. Last time I had this problem, I razored the stuff as best as I could and then rubbed the rest off with 50/50 warm water and vinegar solution. This time around, that is not working as well as I'd like. Anyone have any suggestions for a reef safe glass cleaner? I have always heard using chemicals such as windex or CLR is not recommended for reef tanks.
Thanks,
-j-

[speakerguy]

Muriatic acid, $4 a gallon at Home Depot. It's concentrated hydrochloric acid (HCl). It's safe to use for cleaning, but be VERY careful with it. I spilled some on the driveway and it started bubbling :)

[JimD]

Ive had some luck using salt paste as a mild abbrasive. Give er a shot!

[Reef69]

Id say muriatic acid too..It cleaned the breaks off an old toilet once..and that toilet had some really bad, ermmm, build up..I saw it, true story..

[GaryP]

OK, some safety points here. You should not use straight muratic acid. Dilute it 3:1 or 4:1 with water.

NEVER add the water to acid, ALWAYS slowly add the acid to water while swirling. Its going to get hot so you might want to do this in a stainless sink with your container sitting in some cool water to help cool off the acid/water mixture. I use old vinegar jugs to make up the diluted acid. When you are done, make sure to clearly mark the jug so its clear what it is, especially if you have some left over that you are going to store to use again.

One more thing... Hydrochloric acid will dissolve nylon, so if you use a brush, make sure it isn't nylon or you'll end up with a gooey mess.

[cpreefguy]

Id say muriatic acid too..It cleaned the breaks off an old toilet once..and that toilet had some really bad, ermmm, build up..I saw it, true story..

That reminds me, thanks for showing me how to clean my toilet :sick

[witecap4u]

You can also put some galvanized nails or screws in a 2liter soda bottle and pour some of the muratic acid in and screw the cap on. It will start to react and then blow up in about 5min. You'll want to do this outside though. We used to do this in high school for fun....haha

guess that doesnt help clean the tank though

[GaryP]

The gas that causes it to blow up is hydrogen. Can you say Hindenburg?

[eric]

You should use straight muratic acid.

Gary, You mean "should NOT" right?

Call that being picky, but it's easy to ready the first sentence or two from someone well known (read GaryP) and just remember he said use it straight.

[brewercm]

That reminds me, thanks for showing me how to clean my toilet

They actually used to sell a product called "Pretty Potty" that was nothing more than muriatic acid. Not sure if you can still find it but I believe it was forced off the market because that's all it was.

[GaryP]

[Gary, You mean "should NOT" right?

Yes, thanks for catching that Eric. I edited it. I thought I had reviewed that one real well before posting for exactly that reason. I guess I didn't do as good a job as I thought.

[aedile]

Thanks for all the tips. I'm gonna give the salt paste a try first as the acid sounds kind of scary, but I'm figuring it will probably end up being the acid. I'll let you know how it comes out.
-j-