Converting Saltwater tank to Freshwater

[AntmanMike]

My girlfriend's father gave me his old 150 gallon tank... it was running as a saltwater tank in their basement for around 20 years.

We got it into my house, but it is mildly coated with salt. He cleaned it with bleach, which it still smells of.

I want to know how I can clean the salt out, so I can reapply the silicon and use the tank for freshwater purposes. It would be VERY difficult to move the tank outside to rinse it, so I am looking for something that would be safe for fish.

 

[DAVIDFBT]

Do you have an acrylic or glass tank? If it is glass, you can take a paint scraper to it and break off the salt chunks and then pick them out. Even if there is a little salt in the tank, when you fill it up for the first time, you should do a large water change so the salt that dissolved in the water gets out of your tank.

 

[AntmanMike]

It's glass... I've read about vinegar... it's natural and lightly acidic (which I prefer)... but I'm not sure even minute amounts of it will be safe once it's in water.

 

[Notophthalmus]

What little vinegar residue may be left is harmless. Vinegar will help with calcium (hard water) deposits, but has no effect on salt deposits; for that the best thing is hot water and elbow grease. You'll just have to fill the tank, scrub, and drain it a few times to get all the salt out. Distilled water is more effective at dissolving salt than tap water, so you might use it for the last rinse.

 

[AntmanMike]

Of course, 150 gallons of distilled water is mighty difficult to come by...

 

[will74]

salt

you could use muriatic acid if the vinegar doesn't work. Make sure to wear rubber gloves and dilute it. after the acid all the hard water deposits will disappear and then you have to use plain old elbow grease to get the salt off, as mentioned before distilled water works better on salt deposits.
The second option is to set up the aquarium and run it just like you would with fish in it and eventually the salt will dissolve in the water where the salinity will be so low that it wont harm your fish. What kind of fish are you planning on keeping? Hard water fish like african cichlids will tolerate more salinity than soft water species like south american species.

 

[efors]

Hello!
I had a 30gal saltwater tank that after 6 years I converted to freshwater tank. The only thing I did was to rinse it well with tap water and no problems so far. That was 5 years ago and it is still running. Just scrub using tap water and then remove the salt chunks.

 

[AntmanMike]

I'm preferrent of slightly acidic preferring species, actually, such as loaches, tetras...

 

[ghengis]

Who are the "Silversides", and how did you become their king?

 

[AntmanMike]

A 'Schmerle' is a loach, Schmerlen are loaches.