cleaning hard water marks from old used aquariums

[samiam_orami]

was wondering if anyone had a good method of cleaning up hard water and calcium deposits off the glass from old used aquariums.

I just tried CLR (calcium, lime, and rust remover) with little success.
I've managed to collect quite a large assortment of used aquariums that I would like to clean up if possible ...

aloha ....

[hobogato]

muratic acid - like the stuff used to shock a swimming pool. just watch those fumes and wear some thick rubber gloves. you can also use the extra strong vinegar.

[samiam_orami]

awesome !! thanks ... I'll give it a try ...

[Reef69]

Id go with white vinegar..

[hobogato]

the vinegar would probably be the safer choice.

[matt]

muriatic acid, DILUTED!!! Maybe about 1/2 cup for each gallon, then add more if you need it. Wear gloves and eye protection, and clothes you don't mind burning holes in. If that doesn't work, I don't know what will. Just fill up the tank with the dilute acid and stand back.

[GaryP]

When diluting acid, the acid should always be added to the water and in small portions. NEVER add water to concentrated acid.

[samiam_orami]

I tried the acid at full strength ...
that's some knarly stuff !!! ... spilled some on the concrete and it bubbled like the blood from Alien.

Had little affect on the glass stains however ... helped a little kinda of ... going to keep applying the acid and maybe persistance will pay off ...

thanks again for the suggestion ... if this stuff doesn't work, I don't think anything will ...
aloha ...
SamIam

[NaCl_H2O]

The acid will almost instantly dissolve anythng calcium based, that's why it liked your concrete so much! Full strength Muriatic acid is dangerous to work with, one good whiff and you will be coughing up a lung :sick

I expect the stain is something other than calcium based ... ? I had an old 20g tank once that was badly scratched & algae had grown into the scratches - very tough to remove!

[GaryP]

I agree with Steve. If Muriatic doesn't remove it, it may be something else.

[lax]

the almighty razorblade!

[Dominican]

Soak paper towells really well in white vinegar. plaster the inside of the tank with it and let it sit for a few hours or overnight. Then (it should still be wet) get a razor blade and scrape it clean. My 150 was a disaster when I got it from the previous owner over two years ago. Came out looking like new. Besides, do you really want traces of muratic acid? Do you want to expose your epoxy to that stuff? Just my two cents...

[flyingfish]

I use the Mr. Clean Magic Erasers found in your local supermarket in the cleaning isle to clean the Hard water deposits off of my showerstalls, and sinks, etc. These things are AMAZING. I've tried CLR and Limeaway, even scraped everything with a little straight edged razor. Nothing works as good as the Mr. Clean product. I'm not sure if there are any chemicals you would need to be concerned about leaving residue, so read the box before you try it.

[flyingfish]

I use the Mr. Clean Magic Erasers found in your local supermarket in the cleaning isle to clean the Hard water deposits off of my showerstalls, and sinks, etc. These things are AMAZING. I've tried CLR and Limeaway, even scraped everything with a little straight edged razor. Nothing works as good as the Mr. Clean product. I'm not sure if there are any chemicals you would need to be concerned about leaving residue, so read the box before you try it.

[GaryP]

Muriatic Acid won't leave a residue. I would suggest caution in using something like CLR though. While it is acid based like Muriatic, it also has some soaps in it that will leave a residue. Soaps are what are called "surface active compounds" and chemically bond with surfaces and have a tendency to leach back into the water for a long time afterwards. Most soaps can cause problems with a fishes gills. That's why we usually only recommend acid based products like vinegar or muriatic acid.

Certain bacteria are involved in the scale deposition procedure. They actually help scale deposits form. So, after you decalcify with acid, its usually necessary to clean it with a tooth brush. The same thing applies to coraline algae. After you remove the calcium, there is an organic residue left over. That's what I do when I clean my pumps. Soak it in acid first, then scrub with a tooth brush, then rinse real well and test the pump.

Pumps will usually scale up first. That's because the pressure change in the impeller cavity catalyzes the scale process. I try to clean my pumps every 3 months or so as part of my routine maintenance schedule. I have noticed a lot better performance from them by doing so. The trick is to remove the impeller from the stainless or ceramic shaft when you clean them. That seems to be the biggest problem. You may have to soak it for a while before are able to remove the shaft. A very small amount of scale on the shaft can cause a lot of problems in preventing the impeller to spin freely. If I need to get the pump back in operation quickly for something like a main return pump, I use muriatic acid. If its something like a maxijet that is not a main pump I will use vinegar. Its also a good idea to have spare impellers so that you can just swap them out and get it back in operation quickly. Then you won't be in a big rush to get it cleaned. Just let it soak for a few days, clean it, and store it until the next time the pump is due to be cleaned. Unfortunately replacement impellers can be hard to find and can cost almost as much as a new pump.