Hard Water Stains

I was recently given a 10 gallon tank setup that had been is storage for who knows how many years. The tank is covered in calcium. My son and I spent all weekend cleaning spare tanks, decor, gravel and rocks that we had acquired over the past couple weeks. We thought we had gotten the tank all cleaned up until it started drying and we saw some calcium we missed. Anyways, I have used diluted vinegar, straight vinegar, scrubbed and scrubbed some more I even used a razor blade and that didn't touch it. Any ideas on how to get the stains off? Wouldn't be so bad if it wasn't right in the middle of the glass.

 

What kind of vinegar did you use? I managed to remove some pretty bad hard water stains from one of my older tank with undiluted apple cider vinegar and some serious scrubbing.

 

What kind of vinegar did you use? I managed to remove some pretty bad hard water stains from one of my older tank with undiluted apple cider vinegar and some serious scrubbing.

Just plain white vinegar.

 

Vinegar won't cut it, I live in an area with ridiculously hard and mineral rich water and my tanks are constantly getting covered. I keep my lids tight to avoid evaporation but the lids get so bad they block light. Harsh chemicals like CLR are not an option for tanks as they can cause damage down the road even after you think you've rinsed well enough. What I use along with many other aquarists is a powder product called "barkeeper's friend." The main ingredient is named "oxalic acid" and it's commonly found in many of the foods we eat. It's non-abrasive and can be applied with a rag and some water, it cuts through hard water stains 100% better than CLR (I've used both before.) It's not easy to find in stores but is available on Amazon for just a couple dollars. Oxalic is unusual for an organic acid, which are normally “weak” acids, in that it has a very high dissociation constant—meaning that it acts more like a “mineral acid,” like sulfuric or hydrochloric, than your typical carboxylic acid, like acetic or citric. You could sprinkle pure crystals of citric acid on your tongue (they coat sour gummy worms), and it’s no big deal. If you were to do the same with oxalic acid, you could “burn” the skin right off! Oxalic is about 10,000 times “stronger” than the acetic acid in vinegar (vinegar is a 5% solution of acetic acid). Obviously barkeeper's friend isn't this strong, nor is it made of pure oxylic acid but it's obvious as to why it blows acetic acid out of the race when used to clean hard water stains.

 

I've managed to get some tough stains out with 1:1 water and vinegar solution. Otherwise, after that, then the barkeeeper's friend is a good suggestion, too.

 

Would bleach work at all? I have access to stronger than a 5% bleach.

 

Would bleach work at all? I have access to stronger than a 5% bleach.

No. Bleach is a base, you need an acid to react with the mineral and lime build up. It's like when you do the vinegar and baking soda reaction, it's acid and base reacting, base on base will not react. Thus, bleach will not dissolve hard water stains.

 

HI everyone!

I recently picked up a used 10 gallon tank of kijiji...it is covered in what I presume is hard water stains.

I have googled the issue and apparently vinegar should work. I have been spraying 100% on it and scrubbing like a crazy woman. Nothing. The stains fade when they are wet, then quickly reappear.

I don't get it...should I be filling the tank and soaking it in vinegar? I cup white vinegar in a gallon of water?? Would scrubbing with salt help?

Thank you for any help you can give!

 

I find soaking it awhile works much better and with hot water. Even a paint scraper helps a bit.

 

You could try soaking paper towels in vinegar and allowing that to sit on the glass for a little while. It takes some time.
I use a razor blade to get stubborn gunk off my tank, so that may help too.

 

HI everyone!

I recently picked up a used 10 gallon tank of kijiji...it is covered in what I presume is hard water stains.

I have googled the issue and apparently vinegar should work. I have been spraying 100% on it and scrubbing like a crazy woman. Nothing. The stains fade when they are wet, then quickly reappear.

I don't get it...should I be filling the tank and soaking it in vinegar? I cup white vinegar in a gallon of water?? Would scrubbing with salt help?

Thank you for any help you can give!

Aaaaah! I can help! I just cleaned a 10 gallon tank that was full of very hard water and completely evaporated. Thick white hard 'rock' all over it.
I did this:
Took it outside, rinsed loose stuff, old substrate and detritus off and placed it on a towel in a bare area away from other plants and grass.
Dumped 1 gallon of white vinegar in it.
Filled it the rest of the way, to the rim, with very warm water.
Took glass cover and placed it in the bottom (it was covered with tons of deposits too)
Covered the whole top with plastic wrap and layed a piece of plywood on top to hold the plastic down.
Ignored it for about 10 days.
When I took the plywood and plastic off, nearly all the deposits had dissolved or fallen to the bottom.
I used a mildly abrasive (won't scratch glass) scrubber to scrub (nearly all) the softened deposits off and a safety razor blade to scrape the deposits off of a couple of resistant areas.
I thought the tank was trash!
Sorry I didn't take a 'before' picture!
Finished product:



It still needs a little work, but this was an amazing transition that took very little effort on my part! You couldn't even see through it before. It's now my quarantine backup tank!
Good luck!

 

HI everyone!

I recently picked up a used 10 gallon tank of kijiji...it is covered in what I presume is hard water stains.

I have googled the issue and apparently vinegar should work. I have been spraying 100% on it and scrubbing like a crazy woman. Nothing. The stains fade when they are wet, then quickly reappear.

I don't get it...should I be filling the tank and soaking it in vinegar? I cup white vinegar in a gallon of water?? Would scrubbing with salt help?

Thank you for any help you can give!

If you run your fingers over the glass, does it feel smooth? If so, it is hazing and nothing I know of will get rid of it, however the good news is, once it is filled with water it will be invisible and won't make the tank look nasty.

If the surface is rough to your finger, use a razor blade along with your vinegar.

 

Can you post a picture of it?

 

Thank you both!! You are awesome!!

It feels totally smooth, no roughness at all. So just rinse and fill it up?

It was hard to get a good picture of it...I hope these help though!

Thank you both again for your help!

 

Hmmm...there is also this area of the silicone lifting...it’s a 1.5” strip long, maybe 1/8th of an inch wide..the actual corner seam is okay and the tank holds water.

Can I take the loose piece off and use aquarium silicone on just this area? Do I just leave it?

Oh man, I swear, I should have just paid for a new tank

 

Thank you both!! You are awesome!!

It feels totally smooth, no roughness at all. So just rinse and fill it up?

It was hard to get a good picture of it...I hope these help though!

Thank you both again for your help!

That's what I would do.
I am not sure if something like that product could help or not at this point. I've never tried it. I've just resigned myself to the hazy effect, and haven't had a problem seeing it once its filled.

You are very welcome though.

Can you take a close up pic of that silicone?

 

Just cut that loose strip off with a razor blade. It doesn't look like it extends into where the glass joint is so it's not a problem. I'd not add silicone. If the joint is sealed and doesn't leak, it's fine.

Fill 'er up!

 

Yep I agree. It doesn't look too serious. Just try not to manipulate the silicone too much when cleaning.

 

That is the news I wanted to hear!! Yay!!! Thank you!!

I shouldn’t have to clean it too much more, it has been doused in vinegar a million times. Ha! I will rinse it thoroughly and be very careful while doing so

Thank you so much again!!!! I will get this tank filled up shortly and get my Betta her upgrade!!

 

That is the news I wanted to hear!! Yay!!! Thank you!!

I shouldn’t have to clean it too much more, it has been doused in vinegar a million times. Ha! I will rinse it thoroughly and be very careful while doing so

Thank you so much again!!!! I will get this tank filled up shortly and get my Betta her upgrade!!

I also meant during water changes, cleaning algae and film off the glass. Some people get a little to vigorous or too close to the silicone with aggressive things like algae scrubbers and algae magnets. That sort of thing.

 

Got it!! Thanks toosie !! I will be careful!

This forum is amazing! I am not sure what I would do without all the help I have received here! Many thanks!!

 

I have some hard water stains on the glass of my aquarium and I was wondering how to get it off?

I watched some videos about Bar keepers friend. Would it be safe to use it on the inside of my tank?


Also, if I can’t get the stains off, will it harm my fish?

 

Please post an image

 

If they're on the outside, no, on the inside, I don't know. Some hard scrubbing with Windex or another glass cleaning chemical should work if they're on the OUTSIDE. I don't know about the inside.

 

Vinegar also works well and is fish safe

 

Sorry!
this is the worst one.

 

Razor blade

 

Razor blade

Will that work on the lighter stains?

 

I’m having this EXACT same problem so I’m eager to find out how to solve it!

 

Soak the tank in vinegar and water for a week. It should come off pretty easily.

 

Or vinegar soaked paper towels will stick to the glass for a while, then razor it off with a fresh blade.

 

Will that work on the lighter stains?

As long as its a glass tank there is only one way to find out. Be very careful or get one that holds the razor blade in a handle. Don't ever use a razor on an Acrylic tank.
Stanley 1-3/16 in. High Visibility Mini-Razor Blade Scraper-28-100 - The Home Depot

 

I use salt as an abrasive with a kitchen sponge.

 

Thanks for all the replies! I used vinegar and a blade to remove the largest buildup and it worked. I got all but somebody very tiny specs that won’t be easily visible.

Now I’m working on the rest. I’ll probably leave the stains on the back as long as it won’t hurt my fish. It doesn’t look too bad.

 

As long as its a glass tank there is only one way to find out. Be very careful or get one that holds the razor blade in a handle. Don't ever use a razor on an Acrylic tank.
Stanley 1-3/16 in. High Visibility Mini-Razor Blade Scraper-28-100 - The Home Depot

OMG your pic is throwing me off.......Good one though I like it!

 

Mr Clean Magic Erasers

 

Whats the best way to get hard water stains off a old tank. I've tried scrubbing it, once it drys it comes back.

 

I think most recommend vinegar and scrub, scrub, scrub........I hate it, It does that on my lids.

 

A cleaning product called“ bar keepers friend “ will ease the amount of scrubbing.

Often recommended on many videos.

 

Single edge razor blade, hot water and bar keepers friend