FO tank: 1.022 vs 1.017

[steve102571]

For the past 10 years, I have always kept my FO tanks @ 1.022, but just recently, my LFS told me there are numerous benefits to keepting a FO tank @ 1.017. Is there any truth to this or should I keep my tank @ 1.022??

 

[small triggers]

I wouldnt understand why it would make that much of a difference. Personally, I like 1.025 myself, I think it is more personal preferance than anything

 

[mkroher]

I don't see any benefits. The fish's organs run "easier" at a lower salinity. But I believe I read somewhere that their kidneys can be damaged if the SG is too low for too long.
Now that I think about it more I think it was Joe that mentioned that. I still can't say for sure, but I think kidneys had something to do with it.
/me googles....

 

[jackri]

Only thing I can think of why to keep it so low is for parasites. I personally wouldn't run lower than 1.022 in a healthy tank.

 

[salt210]

for long periods of time I would not go below 1.021

 

[aquaknight]

Originally Posted by Steve102571
http:///forum/post/3135045
For the past 10 years, I have always kept my FO tanks @ 1.022, but just recently, my LFS told me there are numerous benefits to keepting a FO tank @ 1.017. Is there any truth to this or should I keep my tank @ 1.022??
No...
Lower then sea level salinity has two benefits for fish. It lowers the osmotic pressure, so your fish spend less energy keeping internal osmotic pressure. Second, lower salinity water is able to contain more dissolved oxygen then higher, obviously allowing the fish to breath easier.
However, you have already been assisting your fish by keeping your tank at 1.022 instead of 1.0264. There is no point further reducing your salinity to 1.017.
Some of the misinformation about diseases and salinity in the 1.017-1.014 dates well back into the 70's, and is virtually completely wrong. It does nothing. Hyposalinity, 1.009 is only affective against Marine Ich, out of the many possible diseases fish can contract. And you have to maintain 1.009. You start to lose your effectiveness at 1.010.
Yes, there was a big article written that extended exposure to hyposalinity, tends to cause kidney failure in marine fish.