Cycle during hyposalinity

[SittinDucks]

In my quarantine tank that is running 24/7, if a fish gets ich, and I bring down the salinity to 1.009, will the beneficial bacteria survive that low of salinity, or will the tank re-cycle?

 

[brandon429]

That won't cause a recycle, ok for that. A medication event sure can, but that salt range is ok for our filtration bac

Was noticing just the other day on my new fw tank the bottled bac is dual use, fw and salt, all the available ones on the shelf were that way

Though online studies show some speciation given time to adjust relative to salt constant, the seed sources are the same and that's not any particularly harsh change for bac.

how long is the duration of that hold

 

[Chris Fitz]

In my quarantine tank that is running 24/7, if a fish gets ich, and I bring down the salinity to 1.009, will the beneficial bacteria survive that low of salinity, or will the tank re-cycle?

I am wondering the same thing. I have a Kole yellow eye, a minic yellow tang and a PJ cardinal in a 30gal QT with 2 HOB filters and a lot of (possibly too much) flow... I also have a lot of live rock, PVC and fake coral in the QT. Should I take out the live rock or can I leave it for the filtration, looks, and algae for the tang to nip on???

 

[brandon429]

someone check it using no fish in tow, whether that drop kills off bac when the water is brought back to .023 levels.


have a system that has met the submersion timeframes for cycling (not just bottle bac in suspension cycled, big deal here)

after any system that is verified cycled is tested for ammonia digestion, say 2 ppm to zero within 24 hours, its ready for the test. drain the water and add back that diluted amnts above, run it a while and re test for ammonia using the same gear that verified the first ready-to-go. test early on before any bac that may be stressed have died; if your ammonia readings keep climbing as the days go on then ive called it wrong and they're all dead. post results!

The reason the system must be duration cycled (true time underwater way over 30 days and not just bottle bac in suspension) is because that means the nitrifying bacteria will be housed among bioslicks and other insulations that prevent the osmotic shock from happening so quickly.

on websites such as fritz, it says they wont tolerate that salinity drop but those are rather pure cultures, in suspension since you can dump them out of the bottle, and not adhered to bioslicks, so they're weaker.

I know from personal mistake experience that freshwater wont immediately kill nitrifying bacteria that are truly cycle set, I once used the old drain water for my planted tank to refill my vase reef and didn't notice for half an hour. everything was mad, nothing died including microbenthic animals like mini stars I thought for sure it would be a wipe event but nope. I don't know the salinity, it was neutral pH planted tank water in about 80% of the vase for half an hour, kept wondering why corals would never re open after the change