How Fast To Raise Sg

[SMAUG]

Did a 25% water change yesterday, raised SG from 1.006 to 1.008
today my gymnothorax tile is acting sickly.
how fast should i raise the SG?
all other parameters are fine.
Water has been changed again. 60%, and SG is back to being low (1.003)ish
is there any hope for my little guy.
could there be anything else it could be
posted similar in oddball forum

fw moray- HELP!

thanks
-Tom

 

[nmonks]

The limitation on changing SG isn't the fish but the filter. Most euryhaline brackish water fish will go from freshwater to salt within an hour or two. Often much less, in some cases just minutes.

But the filter bacteria need to be acclimated slowly, over a period of weeks, ideally. Often when people say their fish died after changing the salinity, it turns out they went from freshwater to 50% seawater, and the filter bacteria died, followed shortly afterwards by the fish dying.

Cheers, Neale

 

[SMAUG]

thanks. i had read that before, but forgotten in my worry.

i have been raising the salinity slowly so far. 1.006 has taken me about 2 weeks.
What sort of increase in what kind of time span do you suggest?

Does that mean, that the mosty likely cause of my morays problem is 'dirty' water from not being properly biologically filtered?

ps. he seems to be doing a little better in the well established tropical tank for now. breathing has slowed down and hes the right way up.
the big test will be to see if he lasts the night.

 

[nmonks]

He should be fine at SG 1.006 for a while, so I'd leave the tank to settle down now. After a couple of months, assuming all else is equal, you could slowly nudge the SG up to 1.010. But go by small increments, checking the ammonia and nitrite levels afterwards. The goal is to allow the bacteria to adapt/change without the filter crashing. Better to go slowly than too quickly. In the meantime check the pH and hardness. Often, making sure the water is hard (20 dH) and alkaline (7.5-8.0) will give brackish water fish a nice comfort zone even if the salinity isn't quite perfect.

Cheers, Neale

 

[SMAUG]

will do neale
thank you very much