Salinity for Fish Only

[Sergio Henrique]

Hi everbody,

Is very nice to meet you, I'm new in this forum and I realy like very much.

I have a 75 gal fish only tank and I don't have live rocks, just corals skeletons as decor.
I saw a lot of people keep the salinity in tanks like mine 1.016, they said to keep parazites away and do not stress the fish to much.
My question is :

can I keep the salinity in my tank like this ?

and for how long ? This low salinity is just for therapy or I can keep forever ?

thanks

[Reefland]

Hi Sergio Henrique, Welcome to Reefland!

Lower salinity in tanks with only fish and no invertebrates is used to help keep parasites from attacking the fish as the parasites cannot live for long periods is hypo-saline water and if the fish are acclimated slowly to it, can live in it. I personally would keep my salinity lower that I would in a reef tank, but not quite that low. I would target for 1.021 or 1.022.

[Ninong]

Hi everbody,

Hi Sergio, welcome to Reefland!

I saw a lot of people keep the salinity in tanks like mine 1.016, they said to keep parazites away and do not stress the fish to much.

I don't agree with that proposition. In general, I believe you should maintain the salinity in a fish-only aquarium near natural seawater levels. So unless you are trying to duplicate the Gulf of Thailand during the monsoon season, that would be around 34 - 35 ppt (1.024 - 1.026 SG). Especially if you are keeping Red Sea species, I wouldn't go with anything less than 35 ppt salinity. The salinity in the Red Sea ranges from 39 - 42 ppt.

If you are one of those who still believes that lower salinity is better than normal salinity for a fish-only aquarium, then I would say that 1.022 SG is plenty low enough. IMO anything below that is unhealthy.

[Sergio Henrique]

yep, thanks for the tip I will keep the salinity of my tank about 1.022 I think will be better.

thanks

http://www.reefland.com/myaqlog/public.php?userid=5382

[ick sucks]

disease in fish is mostly caused by tempurature fluctuations. i would reccomend keeping your salinity at what is found in ocean water. saltwater fish are not used to low salinity water and doing this will cause them unnatural stress. focus on tempurature stability and your fish will be better off. if your tempurature is going up and down all day your fish will get sick alot. also ocean fish would most likely be found in bracksih water(1.015) if they preffered this low salinity.

[FMarini]

Hi as well-
I'm w/ Ninong on this, you should consider keeping your tank at normal seawater salinities 34 - 35 ppt (1.024 - 1.026 SG). There is little evidence that lowering the salinity does much, until you drop down to 1.009-1.010 when invertebrates (the parasites your concerned about) are killed. Keeping your tank at 1.016 is doing little but saving you money on salt. Fish osmo-regulate regardless
My opinion
frank