Figure Eight Water Requirements

[BeefyG]

Is brackish water an absolute requirement for figure eight puffers? Some sites say contrary to popular belief this is a freshwater fish while other sites say the exact opposite. I know the profile on here says brackish. One site said they do better in brackish when in captivity. What are the consequences of keeping one in fresh vs. brackish?

[fishboyt]

I kept mine in freshwater and they were fine. :)

[imagirlgeek]

Basically, brackish-water puffers kept in freshwater are going to be more sensitive to deterioration of water quality. They will show signs of distress before any other fish. Things to watch for are a general listlessness, or hanging out with their tails curled up and washed out coloration. If you see this, you need to do a water change and add salt asap.

Like Fishboyt said, they can be kept in freshwater, but you really have to make sure the water quality is pristine at all times.

[Nickintex]

They will be VERY prone to fungus in a freshwater set up.

[BeefyG]

Thanks! I'm looking at putting two in a 25 gal tank all by themselves. I'm running a 40gal hydro sponge filter and an eheim liberty 200 HOB. The tank would be mildly planted with enough plants to break lines of sight. Would this work while keeping it fresh? This would be the only tank using marine salt and I'd probably be more likely to mess that up than it would do them good. Plus thats not good for plants is it? I've got some salt left over from the last time I tried GSPs in case I need it in an emergency. I've been too cheap to buy a hydrometer but I guess I can get one if I have to...

[Mzungu]

There are a few plants that do okay with lower-salinity brackish water, such as java moss and java fern, vals, anubias, and some others.

It's not too difficult to do a BW tank, really! I think in the longrun it would be better for the puffers. However, you might find it easier to use a refractometer instead of a hydrometer for a brackish tank. They're more expensive, but lots of people sell their used ones for great prices. The biggest advantage, besides being MUCH more accurate, is that refractometers will measure the lower salinity much better than a hydrometer. Lots of hydrometers out there don't even have gradations to measure salinity below 0.015, and for a planted brackish tank you're going to want to have the salinity lower than that.

[BeefyG]

Lol... I'm glad you posted because I would have just gone out and bought a hydrometer. I really can't spend the extra money on a refractometer right now. The puffers are in freshwater at the store so that would buy me some acclimitization time. I found this on another site: "Note that it takes one CUP of marine salt per 5 gallons of water to raise the specific gravity .005 . You can also just add about two to three TABLESPOONS of marine salt per gallon to your tank to get the salinity around 1.005," Could I just follow that formula to get the right specific gravity? I'd be changing out 5 gallons at a time anyway.

I'm a little confused by the salinity below 0.015 since most of the stuff I'm reading is around 1.005. Did you mean specific gravity?

[Mzungu]

Yes, thank you! I couldn't for the life of me remember the term "specific gravity!"

And yes, I also meant to put a 1 instead of a 0. Apparently I'm a bit loopy today. )

I would wait until you get some sort of measuring device to add salt to the tank. But check around here on HFB in the Fish Market, or on Marsh or Craigslist for anyone selling used refractometers. They go up for sale quite often.

You could follow those guidelines, but with evaporation and maintenance and everything else, it's very hard to keep track of how much salt is in there without measuring it.

[BeefyG]

LOL its Monday... I'll keep an eye out for a refractometer. It looks like the Instant Ocean hydrometer reads down to 1.000 but the resolution is only 0.002 in that range. Still it should hopefully keep me from getting the tank too salty in the meantime. Is there a guideline on how much salinity change is too much?