Can you convert a saltwater tank to freshwater?

[PuffersKick]

I need to upgrade my FOWLR tank. My fish have outgrown their 100 gallon tank. I was thinking of upgrading them to a 200 gallon tank, but I hate to not use my 100 gallon.

So I was thinking I could use my 100 gallon tank to upgrade my freshwater fish who are currently in a 40 gallon tank.

Would I have any problems converting my 100 gallon tank from salt to a freshwater tank? I would reuse my tank, pump, and filter system (which is a bioball system).

Would I have any problems doing this? And what is the best method of cleaning the tank to prep for freshwater?

Thanks in advance for any advice you can give me!

 

[Wiskey]

Sure, my 180 freshwater planted, used to be set up as salt before it's previous owner sold it to me. Just rince the tank and equiptment and re-use, remember some people even add a little salt to their freshwater tanks so a little residue won't hurt.

HTH,
Whiskey

 

[masterswimmer]

First suggestion would be to use the 100 as a sump/fuge for the 200.

If you don't do that, there should be no issues that I can think of going from SW to FW. There are potential issues going the other way though (copper useage in FW)

Russ

 

[PuffersKick]

OK, now another dumb question. Both of my saltwater tanks are "reef ready". Do you have to have a "reef ready" tank for a FOWLR tank? And if not, how do you set up the filtration? HOB?

 

[Wiskey]

you don't 'have to' but I would reccomend it, I love sumps, you can hide your heaters, filters, skimmers, ect,... If you decided not to get a RR tank for your FOWLR tank, you can use hob skimmer, and hob filters, in tank heaters ect, but a lot of the hob equiptment is not as good as the in sump equiptment especially when you are talking about something that will work on a 200 gallon tank.

Whiskey

 

[Pandora]

Hey Puffers, I think you got most of your questions answered already... but just to add--you can also have a HOB overflow system if you don't want drilled or RR. I also agree with Wiskey about loving sumps, if you have a choice.... great also because they expand volume and can act as refugiums.

One more thought on the one you are converting back to FW... try to get most of the sand off the bottom, if you didn't have a BB. You probably already know, but if you have enough CC or aragonite substrate, it could raise the hardness of your FW tank.