How to properly clean a bought-used tank where fish died

[metropolis93fan]

bought a used small tank from a kid to use as my fish "hotel" when I stay at my parents house more than a few days. It's filthy and I want to make sure that whatever disease finally killed his betta (never cleaned it... his dad told him if it had a filter it wasn't necessary. Ha!) Best way? The caked on gunk on filter intake really worries me. And it's one built for that specific tank so can't be replaced

 

[DragonScales+Doubletails]

just spray it down with a water source under pressure, like a hose for instance. Do NOT use soap or bleach of any sort

 

[Back in the fold]

The best thing to clean it with is a really strong saltwater solution and a new (never used) scrubbing pad. Rinse well , air dry and you're good to go. As for the caked on gunk on the filter. Soak it in white vinegar overnight, rinse really good and that should do it.

 

[metropolis93fan]

Thanks!

 

[OliveFish05]

You can use warm water to soften some residue, and scrub it with a tooth brush. You can also soak it with vinegar for especially tough things or hard water deposits.

 

[Rocky998]

You can use warm water to soften some residue, and scrub it with a tooth brush. You can also soak it with vinegar for especially tough things or hard water deposits.

Vinegar is your best friend for heavily cleaning all things aquarium related.

 

[Uberhoust]

Guess I am old school, I have and still use bleach to clean old tanks. I know it will work on most everything. Just make sure to rinse well. If you don't let your hands touch the bleach you will find it rinses very easily. A lot of people mistake that oils that leave their skin as a residue of the bleach.

 

[TwoTankAmin]

I have bought a number of used tanks over the years. Some worse than other and I always use the same system. Normally this must be done outdoors as I have tanks 1rom 150 gal down to 5.5. The methods below are for glass tanks.

I set them on a raised surface in a place where I can easilly disperse the water and not kills things by not being able to rpead it out. I am cleaning for two specific things and there is a bunch of rinsing and maybe some fine hand cleaning to do.

If there is a white hard crusty coating

I fill the tank with a very low pH water. I do this by adding muriatic acid. But this is dangerous stuff to use if you do not know what you are doing. So adults only and ones who understand how carefull to be. For others I suggest white vinegar- stinks but it works. You will need more of this than the acid.

Fillt the tank with water adding the acod/vinregar as you got. let it soak for about 20 or 30 minutes at least and longer is often better. Tools you may need: Algae scraper with metal blade, algae pad, a single edge razor and Q-tips.

Do not put your bare hands into the tank if you use the muriatic acid.
After the soaking, use the scraper to remofe buidup on the glass. Use the agae scrubber for uneven surfaces, used the single edge razor for tight spaces. For the finer work you can wait until your drain the tank to do it.

If you must put you hands/arms into the tank with acid, wear protective gloves. Long kitchen gloves are good for not having to go too deep. Armpit length must be used for deeper work.

If the tank is really crusty it may not all come off doing just the above. You will needs to go over them again using the Qtip or a tiny pies of a sponge dipped in pure venegar ior a stronger consentration of the acid (wear gloves). Apply the liquid to the stubborncrust. Let it sits ofr a nut and then use the razor or scrubber pad to remove. Repeat as needed.

Rinse the tank. you do not need to fill it, you reed to run water downs the side, under the edge of the top frames and the bottom glass. Dump the water. Tank is good to go from this faze.

If the tank needs disinfecting

Bleach is yopur friend Chlorine kills and can even dissolve almost anything organic, The key to this is chlorine gas. This take work to get intoa liquid like bleach. Most of household bleach is water. The good thing about it is that chlorine evaporates and leave no trace behind. Use only plain unscented bleach. Do not use the low splash but concentrated is OK.

Plant keepers use a 19-1 (water to bleach mix to kill algae). You can go a bit stronger. But bear in mind that if you want to sterilize a 100 gallon tanks you would need between 5 and gals. of bleach, these fays that is going to cost about %20 - $50. One way to reduce this is to fill the tank less, and then to use a small pump and hose to wash down the unsubmerged glass. Besure to gieve this glass a fewm minute
wash.

When done, drain the tank. Then use just water to rinse it down and empty it. All of the clorine will evaporate and any small amounts of additives will be so diluted that they wont matter isfthere are any at all.

I have never ever lost a single fish doing the two above methods. Chlorine is only dangerous if it is disolved in the water. Nothing dry will have any chlroine in or on it. By volume, I use more chlorine for tank work than any other chemical. But I use a couple of HOT Magnums using the micron Cartridges and those ae cleaned by being put intop a 25% bleach solution overnight. The are reused after having the dissolved gunk rinsed out and they are completely fried.

 

[FishNturt808]

I have bought a number of used tanks over the years. Some worse than other and I always use the same system. Normally this must be done outdoors as I have tanks 1rom 150 gal down to 5.5. The methods below are for glass tanks.

I set them on a raised surface in a place where I can easilly disperse the water and not kills things by not being able to rpead it out. I am cleaning for two specific things and there is a bunch of rinsing and maybe some fine hand cleaning to do.

If there is a white hard crusty coating

I fill the tank with a very low pH water. I do this by adding muriatic acid. But this is dangerous stuff to use if you do not know what you are doing. So adults only and ones who understand how carefull to be. For others I suggest white vinegar- stinks but it works. You will need more of this than the acid.

Fillt the tank with water adding the acod/vinregar as you got. let it soak for about 20 or 30 minutes at least and longer is often better. Tools you may need: Algae scraper with metal blade, algae pad, a single edge razor and Q-tips.

Do not put your bare hands into the tank if you use the muriatic acid.
After the soaking, use the scraper to remofe buidup on the glass. Use the agae scrubber for uneven surfaces, used the single edge razor for tight spaces. For the finer work you can wait until your drain the tank to do it.

If you must put you hands/arms into the tank with acid, wear protective gloves. Long kitchen gloves are good for not having to go too deep. Armpit length must be used for deeper work.

If the tank is really crusty it may not all come off doing just the above. You will needs to go over them again using the Qtip or a tiny pies of a sponge dipped in pure venegar ior a stronger consentration of the acid (wear gloves). Apply the liquid to the stubborncrust. Let it sits ofr a nut and then use the razor or scrubber pad to remove. Repeat as needed.

Rinse the tank. you do not need to fill it, you reed to run water downs the side, under the edge of the top frames and the bottom glass. Dump the water. Tank is good to go from this faze.

If the tank needs disinfecting

Bleach is yopur friend Chlorine kills and can even dissolve almost anything organic, The key to this is chlorine gas. This take work to get intoa liquid like bleach. Most of household bleach is water. The good thing about it is that chlorine evaporates and leave no trace behind. Use only plain unscented bleach. Do not use the low splash but concentrated is OK.

Plant keepers use a 19-1 (water to bleach mix to kill algae). You can go a bit stronger. But bear in mind that if you want to sterilize a 100 gallon tanks you would need between 5 and gals. of bleach, these fays that is going to cost about %20 - $50. One way to reduce this is to fill the tank less, and then to use a small pump and hose to wash down the unsubmerged glass. Besure to gieve this glass a fewm minute
wash.

When done, drain the tank. Then use just water to rinse it down and empty it. All of the clorine will evaporate and any small amounts of additives will be so diluted that they wont matter isfthere are any at all.

I have never ever lost a single fish doing the two above methods. Chlorine is only dangerous if it is disolved in the water. Nothing dry will have any chlroine in or on it. By volume, I use more chlorine for tank work than any other chemical. But I use a couple of HOT Magnums using the micron Cartridges and those ae cleaned by being put intop a 25% bleach solution overnight. The are reused after having the dissolved gunk rinsed out and they are completely fried.

Wouldn’t muriatic acid eat away at the silicone seams?
I’ve used it to clean rocks and seal cement. Never thought to use it for hard water stains

 

[TwoTankAmin]

The trick with the acid is that you are diluting it with a lot of water. I have learned how to get it to the point where it works and I can usually put my bare hands into the water. The worst it should do is sting ever so slightly. More than that and the gloves go on. Muriatic is already diluted. I add it to my Altum angel tank to hold the water down in the 6.0 range. I dose 1 or 2 ml of it into a 55 gal. max. But I have a contant digital monitor so I can add it several small er additions until it hits close to the targetted level

But I have been at this for some time which is why I suggest using white vinegar instead for those less wanting to take the risk of overdoing it. But it costs more, especially as the tank size goes up. It also stinks I have not yet burned through a gal. of acid in about 7-8 years, maybe more. It was origianlly bough for use in a swimming pool and I swiped it from our shed. Also, I have never had a used tank I treated with both bleach and acid spring a leak. But I have never had other new tanks do so. I have the following used tanks: 150, 125, 75, 40L 2 x 33L, 2 x 20L. I have had newly bought leakers ultimately thrown out and mostly replaced: 75, 45, 20L 10 gal tanks.