F8 Puffers - Freshwater to Brackish

[jayne]

Hi folks

About 6 weeks ago I bought 3 F8's who were being kept in freshwater at my LFS.

I set them up in their own tank,still in freshwater,fully intending converting them to brackish more or less straight away.

But,due to various circumstances,I haven't as yet and they are still in freshwater,which is hard and alkaline but totally salt free.They are doing really well,growing and eating and are real little barrels these days (they were slim jims in the shop).

So anyway,I now have more time to spend at home with them so I'm thinking about their water again,but it seems from what I've read that they maybe don't need brackish water until they get older.I'm in no way trying to be controversial ,and I know that this can be a very heated subject,but I was wondering if there is anyone who has actually tried to keep F8s in freshwater until they become adults and if they did,was it sucessful?

My understanding is that they can be more prone to parasites etc. when kept in freshwater,is this true?

Just to reiterate,I'm not asking this because I can't be bothered to add salt,it's here ready and waiting,it's more just because I'm curious and would love to hear accounts of other people who have kept these puffers long term ie for more than 12 months.If I thought that my fish were in any way suffering or were less than 100% happy and healthy in freshwater at the moment I wouldn't hesitate,but they are doing so well that I'm slightly unsure about whether to interefere.

What I would really like is feedback from people who have actually done it,or tried to do it,so that I can build up a picture for myself.

Please don't flame me,I'm not trying to start a fight,or skimp on my fishes' care,but I've kept fish for over 30 years now(God I'm old ) and sometimes things seem to become fact without much evidence to back it up,I'm just being pedantic and asking for evidence

[Agnate]

Here's the scoop: F8s *can* live in Freshwater for their entire lives. However, after a little research, they/we decided that F8s seem to thrive best in a slightly salty environment (around an SG of 1.005). The reason is that the salt helps bring in additional minerals and such that the puffers would otherwise not have, and also helps to prevent certain freshwater diseases (keeping their immunity system healthy and high).

Thus, you can technically keep your puffers in freshwater, but you'll find that as time passes, you're going to love your puffers more and more, and by keeping them in brackish conditions, you'll reduce their chances of disease and death.

And don't worry about being flamed. We're a very calm bunch unless your intent is actually to hurt our cute little puffer friends, which you clearly aren't. It's perfectly logical to question internet information, as a lot of it isn't very reliable. Luckily, you've come to the right place about puffers, as we're not about just trying to make them survive; we're about making them thrive!

[jayne]

Thanks Paul,thats exactly the type of feedback I was hoping for

I'm always trying to do the best for my fish and I would never do anything to compromise that,but sometimes I think that things can be considered 'the right way' just because that's how they're done,rather than because that's how they should be done.

I am in no way trying to say that F8s shouldn't be kept in brackish water for at least part of their lives,I'm just curious about people's experiences of keeping them in both fresh and brackish conditions long term.

BTW I love your saying 'we're not about just trying to make them survive; we're about making them thrive!'

That should be the motto of this site

[CoreyK]

There isn't really a "right" salinity for estuarine species like Figure 8's; they are, afterall, euryhaline creatures from a dynamic environment. But for reasons unknown to us, in captivity they seem to do best in light brackish water.
The fact that a member kept one alive for 18(?) years in light brackish is very telling.

[Nick]

It seems that they live about 5 years in FW, and over 15 in brackish, thats why they're generally kept in brackish though they're typically collected from freshwaters.

[Myaj]

I believe RTR (who is the member who did a lot of testing and kept one alive 18 years) found that they do best in low salinity levels.. but they also do good in freshwater IF it is very hard and alkaline. In fact, if I remember correctly, his theory was the pH and hardness was more important than the salt.. but it was easier to recommend the low salinity because then the salt will buffer softer tap water into something more comfortable for the puffer. The buffered water/higher levels seems to keep the fish's immune system strong and they live a more healthy life.

Now, I could be remembering incorrectly, but I know its been discussed. Figure 8's don't do well in soft or mid-hardness freshwater, but in very hard freshwater they can do very well. I just don't think anyone got around to long term testing to find out for sure, but its strongly suspected.

So what are the levels of your water? What might be "hard" to one person might be pretty soft to someone with "liquid rock" water, hehe.