Cycled Tank Turned Brackish...

[KrayzieVanh]

I had a cycled tank that I just turn brackish today and added a spotted puffer. I just realized and was wondering- would the salt kill the bacteria? I used 1 tablespoon for every gallon.

 

[penguinpimp1990]

what salinty/specific gravity did you raise it to?

 

[KrayzieVanh]

what salinty/specific gravity did you raise it to?

I didn't buy a hydrometer (??) so I don't know the exzact numbers.

 

[JJ1234567]

First mistake, you need a hydrometer. Second mistake, GSP's start out in mid level brackish, but as they age need to slowly be taken to full marine. So a Hydrometer is your best friend, although I prefer the refractometer, it is much more precise. Also, what size tank do you have this little guy in?

 

[penguinpimp1990]

yeah like he said a hydrometer is a MUST in a salt/brackish tank or even better a refractometer. Some say refractometers are overkill for brackish tanks but i totally disagree. They are far more accurate and will become very handy when having live plants and increasing SG when acclimating new fish. I bought one off liveaquaria.com for $40 and its been the best $40 ive spent on my tanks so far.

 

[nmonks]

Penguinpimp --

I may be one of the people who say refractometers are overkill!

Good quality floating or swing arm hydrometers are, in my experience, accurate enough for brackish water fish. No euryhaline brackish water fish needs an exact salinity, by definition they tolerate ranges of salinities. In the case of a green spotted puffer, anything from 1.010 to 1.018 will be fine, and changes up or down with each water change will not only be harmless but possibly helpful. There's good evidence that varying the salinity cuts down on parasites and triggers spawning. So even if you're "aiming" for 1.015, but the hydrometer is off by one or two points in reality, it doesn't matter.

I would agree that with live plants, accuracy may be more important, and likewise marine invertebrate tanks tend to need accurate measurement of salinity.

Either way, your basic point that KrayzieVanh would do best forgetting about weighing or measuring salt by the spoonful is good. While, in theory, you're aiming for around 15 to 35 mg of salt per litre, because salt absorbs water from the air, once the box is opened, relying on weight or volume becomes increasingly inaccurate. A cheap, relatively accurate floating hydrometer will cost around $5; more accurate swing arm hydrometers can be anything from $15 to $30.

Cheers,

Neale

 

[KrayzieVanh]

Thanks for the replies but I still haven't gotten the answer that I was looking for. I will probbaly head out today to get a hydrometer. The problem is with the bacteria that was previously cycled in the tank, would the salt kill them off and restart the cycle?

 

[nmonks]

Yes.

The bacteria in a brackish aquarium will be freshwater ones up to about 1.005 or so, and after that, they're the marine ones. At least that seems to be the case.

If you increase the salinity slowly, say, over a month or two, then the marine bacteria will grow while the freshwater ones die off. While the filter won't be stable or operating optimally, the fish should be okay. Just don't add any more fish or over feed. Run frequent nitrite tests, and do regular water changes. In this case, I'd take the salinity up the SG scale by no more than one point a week, i.e., 1.001 to 1.002 the first week, 1.002 to 1.003 the next week, and so on.

Cheers,

Neale

The problem is with the bacteria that was previously cycled in the tank, would the salt kill them off and restart the cycle?