From FW to SW

[CandiBug2]

Right now I'm cycling a FW tank. I really really really wanted a SW tank, but couldn't afford the startup costs. LR is really expensive around me. Anyway, I would really like to start a SW in the next year or so. I was just wondering... Would I be able to somehow transform my FW tank into a SW tank without having to repeat the cycling process? By the time I'm ready to have my SW tank, my FW tank will be well established. Would I be able to just change the water and still have a cycled tank? Is the bacteria the same for both types of tanks? OR... would I even be able to seed a SW tank with FW tank media?

Does this make any sense??

[OrionGirl]

There's not a really good answer to that question. The bacteria that work in either system have not been firmly identified, so there's no way to determine if they are the same or not.

Anecdotally, SampsonNY converted his established FW tank to SW by bringing the salinity up in a weekend...And never experienced an ammonia cycle. So, you may be able to convert your tank with ease--but make sure you have plans for the fish in your tank! They won't make the conversion even if the bacteria do.

[mogurnda]

According to Bob Fenner at WetWebMedia, nitrifying bacteria are very sensitive to changes in salinity, so it may not work. Unfortunately, he doesn't provide any real data, so it may be pure hooey.
One problem is that the stuff you have in the tank, live sand, live rock, etc, will be very different from the stuff in a FW tank.
As far as the price of live rock, order online. You will get more choices and better rock that what you can buy locally. There are plenty of people here who can recommend good suppliers, depending on what you want.

[CandiBug2]

Thanks for the info. I'm going to buy another tank, looks like I'll just have the best of both worlds :)

When cycling a SW tank with raw shrimp, do you leave the shrimp in for the entire duration of the cycle or is there a point when you can take it out?