Aaargh! How do you clean SW stains from glass?

[Thaiboxer]

Hi all! I'm very frustrated right now! Here's the background...

Just got a 125 gallon from a guy, it's been sitting empty for 3 years but was previously a saltwater tank. It appears that he let water evaporate for a long time because the top 3-4" of the tank have water deposits that are really hard to clean. I called him and asked, and he promised they were just water stains - nothing else going on.

Here's what I've tried:
1. Bleach/Water solution with green scrubby pad. No progress.
2. Vinegar with green scrubby pad, then steel wool. Tiny tiny progress, but it'd take years to clean.
3. CLR/Water (50%) with green scrubby pad. It made a dent, but still not a lot of luck.

Tonight I'm planning straight CLR with a razor blade. Any other ideas? I've been fortunate not to scratch the glass so far.

And yes, I'm planning to thoroughly rinse and re-seal the tank when I finish cleaning it.

Thanks in advance!

 

[snapcrackler]

Try some hydrochloric acid (muriatic acid)

from hardware store, or in the swimming pool chemical section of your favorite store that has swimming pool stuff. This contains hydrochloric acid.

Dilute a little bit, wear protective eyewear/gloves/clothing and brush on, let soak.

 

[tkos]

I would soak a twoel in vinegar and let it sit on top of the white stuff for quite awhile. this may help soak into the crud and get it loose.

Or else go for broke and get some muriatic acid from the hardware store. It is used to clean concrete and is really nastey stuff. Make sure to use goggles and really thick gloves and old clothes if you use ti though.

The razor blade might just do it as well.

I have also heard that oxyclean works wonders on some tanks.

 

[tmcpeek]

Try muratic acid as a last resort. The stuff is nasty. Wear gloves and a mask (or make sure you are outside). I just used muratic acid to clean my concrete basement walls and when the mixture of acid/water touched the concrete, it smoked and let out a really foul odor. If you end up using it, you may want to reapply the silicone. It may weaken it and cause leaks.

Good luck!

 

[fishfreek]

I would do the soakign with vinegar first. Acutally let it soak so if that means putting the tank on its side and pouring vinegar on it then try it. Instead of using steelwool ( i really cringed when i read that) use a stright razor blade or one of those metal edged algae scrapers. HOld the edge at a low angle. 30* or less and also approach the residue with the blade at a 45* angle on the plain of the glass. Kind of like a snow plow blade. If these are really mineral deposits the vinegar should eat them away or disolve them enough that they can be scraped.

 

[Thaiboxer]

I soaked it in vinegar for more than 30 minutes last night with very little luck. I'll try CLR with the razor tonight, and if that doesn't work I'll go with muriatic acid.

I'll let you know how it goes! Thanks for the input!

 

[leafyseadragon]

In high school I worked with hydrochloric acid as a lab assistant. That's some nasty stuff. I opened the glass jug and was amused and shocked when I saw fumes coming out, good thing this was all done under the hood.

If you dilute the acid, remember to pour the acid into the water and not the other way around. This process should also generate lots of heat, so if your mixing container is glass, make sure it's Pyrex.

 

[reefrunner69]

I would fill the tank, add 3-5 galloons of vinegar and let it sit for a day or two...should remove it all witl little or no work on your part.

 

[Thaiboxer]

I didn't get a chance last night, I was building my new stand

Hopefully I can do it tonight, or I definitely will early tomorrow. Thanks for all the advice, I will try everything here - if nothing works, I'm going to take a rifle to the tank (j/k)