Sorry, I missed that. The tank is practically cycled (old water, old filter).jake_vdb wrote:Please read the whole post.Corvus wrote: 1. The tank is not cycled, so there are basically no bacteria yet which could be killed by salt.
@boxermom:
During my start with T. nigroviridis I tried to simulate salinity changes as they occur in the mangroves of SE asia (but with a much lower cyclicity of two weeks instead of twice a day). Reaching low salinity (density below 1.003), some showed a bad condition (heavy breathing, black belly) which rapidly changed when salinity started to rise again (up to 1.02). It was a small tank, small specimens. By the way, neither nitrite nor ammonia did occur during the changing salinity, so it seems most bacteria adapted sufficiently. Nitrate rose extraordinarily (dead bacteria I guess) but wasn't dangerous due to the daily water changes. Therefore I assume the bad condition of most puffers in lfs is due to the lack of salt (osmotic stress for the animal adapted to higher salinity), although - as you note - other factors such as stress from overcrowding and transport add to it.
Most fungus (may be also true for internal parasites and some bacteria) are not tolerant to salinity changes at all. There are of course adapted species, which life in brackish and marine water, but they don't like water changes either. Salting up is my standard procedure for curing e.g. feeder guppies from fungus and ich. Since I use bacteria from long time running brackish tanks I do not recognize messed up biology these tanks. It also works for sick brackish puffers.
If the medication products recommended by you does not affect bacteria it should be safe to use them.