Turing an established FW tank to brackish??

[arynnoctavia]

I have two GSPs in a 45 gallon FW tank. They were sold to me in FW, but in researching them, I've found some expert sources that say they need brackish (I've also found some that say they prefer fresh, and some say they can be in marine tanks when full grown). More of the sources say brackish than anything else, so I was going to go with that, but I've got a few questions.

How? I've read articles on how to set up a brackish tank, but non on how to turn an established FW into brackish if there are currently inhabitants in the tank. I know I should raise the salinity bit by bit, instead of all at once, but how should I go about that? Won't the bacteria that built up when I cycled the tank die if I raise salinity? Will the tank have to go through mini cycles each time I raise SG? The tank isn't planted, so at least I don't have to worry about killing plants. The two GSPs are the only living inhabitants.

Gravel? Right now there's gravel in the tank, but I've read many brackish set-up guides that say to use crushed coral or sand. Is sand or coral necessary, or will gravel be okay? Should I scoop out all the gravel and replace it?

Right now the puffers are still pretty small, the biggest one is still about 2 inches. Should I start the salinity rise now?

Anything else I should know before doing this? I want to do this with as little stress to my puffers as possible.

[trekenk]

Hello and welcome to TPF, you have come to the right place. GSP do prefer high end brackish and as they get older full marine. You are also going to need to upgrade your tank as they need a min. of 30 gallon each. If they are small under 2 inch you should be able to get away with your 45 gallon for a while, but to answer your question yes they are ready for brackish.

Here is a link all about GSP.
library/puffers-in-focus/an-introductio ... d-puffers/

Here is a link on how to turn your tank to brackish, although you will eventually want to slowly go full marine, with live rock and skimmer for filtration.

viewtopic.php?f=5&t=19348

Good luck with them and stick around lots to learn.

[arynnoctavia]

Thank you, that is exactly what I was looking for.

I figure it works out well, because I will leave them in this tank (with gravel) and brackish conditions until I move them to a 60 gal, at which point I can restart with live rock and full marine conditions.

Thank you.

One more question: How will I know they are ready for full marine (and bigger tank)? Is there an inch long threshold that I can take to mean they're adults?

[Pufferpunk]

Please check out the GSP article in our Library. It pretty much tells you everything you need to know about them. There is a great sticky in this forum on raising FW to BW.