Getting salt out of tank

[Cjbear087]

Guys so I just got a second hand tank which was used for salt water and I want to use it as a freshwater tank. I have hosed everything off as much as I can but there a some hard patches of salt which water and scrubbing will not get off and I am worried when I have a fish in it the salt will dissolve and kill the fish. What is the best way to get any excess salt out and sterilise the tank in the process? Thanks

[AdamS]

Sorry I can’t help, but following this thread as I got a used aquarium and am in the same situation. 

[Tony s]

I think I might just fill the tank and see if it dissolves on it's own. This would do 2 things. 1- it would dissolve the salt hopefully or at least soften it. 2- it would perform a leak check on the tank. Especially important for a used tank.

as for disinfecting it. if it's been dried out for a while there is really no need. not much of anything is going to survive being dried out. or you could rinse it in a 3% hydrogen peroxide solution and dry it out again

Edited May 9 by Tony s

[jwcarlson]

Fill it up and pump water around in it.  It might also be mineral deposits.  Vinegar will help with the minerals.

[doktor zhivago]

Vinegar and hot water would probably do the job. 

[face]

My old 110 had the same problem when I got it I used a plastic razor and some vinegar if I’d have really wanted to get it all I might have used citric acid

[T. Payne]

I second the vinegar and razor blade method. Just be careful not to scratch the glass.

[Cory]

Unlikely there would be enough salt left to make a difference. Fill it up, let it sit, change water after a week if you're worried.

[Lennie]

Im not sure if the question here is purely salt. Reef tank and saltwater tank salts have many things added besides the salt itself, as people use RODI and use these reef/salt mixes to reach ideal tank water.. You might be seeing the residue of many things and I don’t think it is just salt, if any

[lefty o]

its probably calcium and other minerals, water dissolves very easy.

[face]

On 5/9/2024 at 5:20 PM, Lennie said:

Im not sure if the question here is purely salt. Reef tank and saltwater tank salts have many things added besides the salt itself, as people use RODI and use these reef/salt mixes to reach ideal tank water.. You might be seeing the residue of many things and I don’t think it is just salt, if any

Ya In my case it was dead coralline algae with a bunch of hard water stains around it 

[jwcarlson]

Put a little vinegar on it.  That will help you tell what you're dealing with...

Edited May 10 by jwcarlson

[AdamS]

In my case I used bar keepers friend to remove the hardwater/salt stains on the outside. 

[CMcDermott]

Marine salts contain a lot of calcium carbonate as well as the salt so it's probably carbonate deposits. Use a couple of layers of paper towels soaked in vinegar stuck over the deposits and let sit for a couple hours, then scrape what's left with a razor blade and repeat until the deposits are gone. The glass may be etched under the mineral deposits, the etching usually looks like cloudy raindrops on the glass and you can't scrape that off.