Question about converting a saltwalter tank to freshwater.

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CaliFishGuy

Jack Dempsey
MFK Member
Jan 25, 2017
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I just bought a used 125 gallon tank. It was a saltwater tank. The tank has live white sand and live rock in it. I want to use the tank as a freshwater tank now. Can I use the white sand and live rock for my freshwater tank after some cleaning or will it be unsafe for my freshwater fish. Thanks in advance.
 
You will need to wash and rinse it pretty well but it should be fine with the exception of having the rock that is typically seen in saltwater in your freshwater tank.

You will probably want to be sure about the substrate though. Some saltwater substrates can have effects on the ph.
 
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After a good cleaning, you could use them both if you wanted. But i'd personally replace it all. Sand is cheap, and rock isnt bad depending on the rock

typically liverock is very porous since thats the biofilter. Very porous rock tends to be very rough. Fish are dumb when spooked and will probably injure themselves on the rock.
 
You are going to have a long cycle. Saltwater rock has lots of bacteria and life on and in it. I would just sell the live rock and buy dry. Live rock costs a lot more, so you might be able to trade it in at a LFS.

I tried reusing live sand. When I rinsed it in freshwater tons of bristle worms, micro stars and other stuff started to come out and die. It was so gross I just tossed the sand.

You can reuse it but it is more trouble then it is worth. Sell it or trade it. If you go on a local reef site you can try and find someone to trade live rock for dry.
 
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Awesome thanks for all the information guys! I think I'm going to use the material and try a saltwater aquarium with a 55 gallon tank that I'm not using right now.
 
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