fw to sw?

Many people use mollies or guppies as the first fish introduced into their SW aquariums.  Dave Tea has a thriving population of SW mollies introduced into one of his greenhouse tanks. They were removed from SeaBase as I recall.

Most fish that you would consider freshwater that can be "acclimated" to saltwater I would not really consider freshwater fish at all. They are better classified as euryhaline.

A good example is the Tetraodon biocellatus in my avatar. They are a secondary fish, most commonly found in freshwater in nature, but in aquaria they are usually more healthy and live much longer in brackish water. People on thepufferforum.com have successfully kept them long term at full marine sg also.

A good guide to euryhaline fish is the Brack FAQ link link2
Many of these fish will tolerate the full range of specific gravity as they may migrate from freshwater rivers, through brackish estuaries, to the ocean.


Edited by trunks - September 22 2007 at 1:52am

Most, if not all of the brackish fish do great. Monos, scats, archers, puffers, dragon and panther gobys.

so how exactly do you do it i have tried and killed numerous guppies and mollies.

The rule on thepufferforum is no more than .002 change in sg per week. Although I think this rule is more for nitrifying bacteria than fish. In any case, either make the transition very slowly, or try different guppies/mollies, as some species/types are more salt tolerant than others.

When my frogfish was still living.... I tossed a couple of guppies in the the tank, with nothing more than floating the bag for a few minutes.  I actually had one guppy survive for quite a while... I'm pretty sure you could acclimate guppies pretty easily.

i am going to try mixing a tank of brackish water and throwing them in there for a week or so and then make it more salty over time. i am hoping it would work i have tried to acclimate them over a few hours with a drip line, but it did not work the next morning i found them dead. so lets try it this way and see what happens.

Well, I have "acclimated" a male and a female guppy into my brine tank. They have been there since I posted that I would try earlier this week. They seem to be doing fine as of today.  I will give them a little longer before I decide if I want to try putting them in my "display" tank

If they dont make it, I wont feel to bad.  They are just feeder guppies that I feed my lion fish for a little treat

pa_reptileman_4 wrote: so how exactly do you do it i have tried and killed numerous guppies and mollies.