I have a FW tank with a Paradise Gourami, African Cichlid, Chinese Algae Eater, and Cory Catfish. I really want to get a GSP, F8, or small Fahaka, but I want to make it BW. The pet store I am getting it from is keeping it in FW, so my plan was to get it and slowly convert my tank to BW (1.000 - 1.005 or so???). Can these fish I already have tolerate BW, or will they not survive?

Doing a quick Google search tells me that the Fahaka puffer is actually more freshwater than brackish, while it can handle brackish it just does better in freshwater. Plus it gets pretty darn aggressive.

The Green Spotted Puffers needs brackish to full on marine water, again per Google, so him and the Fahaka should not be mixed. Also, again, aggression is an issue with just about any puffer and the GSP is no exception.

It looks like the Figure Eight can handle both brackish and fresh water though is more often found in fresh water. Though of course most people state it needs brackish in the long run to thrive.

Despite these three fish not seemingly a good choice to mix with each other the biggest concern is that your other fish are not brackish water fish. While an African Cichlid of any kind can greatly appreciate the presence of salt in their water they are by no means brackish water fish. The same goes for the cory cats though they appreciate salt in their water to a much, much lesser extent I feel.

Gouramis are straight up freshwater. Also they tend to have longer fins and move fairly slow. So if you did happen to house them with puffers they would probably just end up being tormented.

All-in-all I would say keep two tanks. Keep a Fresh Water tank and a Brackish tank if you really want to have fish of both kinds. Also - that African Cichlid may some day get super aggressive and kick your gourami's tail. That's just how they are. The cory should be fine as no one seems to really bother them for the most part and they are quick to leave a territory if they know it's not a good place for them.

Oh - forgot the Chinese Algae Eater. He also is strictly freshwater and probably wouldn't enjoy any additional salt either. And there is a chance some day he's going to turn into a meanie too and start getting aggressive. Again, it's just who they are.

Good luck and I hope this helps. Sorry if I'm coming across a little negative. Just don't think the set up you're going for is going to be a success.

__________________
I like big fish tanks and I can not lie. You other brothers can't deny.

Thankyou for your reply. Knowing that the fish I have are strictly freshwater helps a lot. I just did not know if i was going to get lucky and be told they could tolerate brackish water.

It was never my intention to have multiple types of puffers in a single tank. What i was trying to find out is which would fit in best with what I currently have. What i really want is the gsp. I'm thinking that while he is smaller he can be in the fresh water tank. In a few months if all goes well, he would be moved to a brackish water tank of his own.

Just be aware that the cute, baby GSP may still inflict some harm if housed with other fish. Even in just a few months time they can wreck havoc. Those puffers can be cheeky punks despite being adorable.

__________________
I like big fish tanks and I can not lie. You other brothers can't deny.

__________________
http://s1050.photobucket.com/albums/...eefingMadness/