Best Salinity Level for fish only?

In the past i went for 1.024 {used Instant Ocean products}

 

Anything from 1.020-1.026. NSW is 1.026, so a lot argue that is what all tanks should be run at. However, lower salinity levels means fish use less energy expelling the salt from their gills. So I would lean more towards 1.022 to give a little buffer in case salinity increases or decreases.

 

yep +1

 

We run 1.020 - 1.023 in our FOWLR setups. In the past, I've run FO tanks as low as 1.018 with no ill effects.

 

I try to run my tank(reef) in the middle of the range. Usually 1.024-1.025. I figure it gives me a buffer both ways.

Probably not a big deal for fish only but I'm not a big fan of Instant ocean.
I just mixed about 300 gallons and Alk is about 4 and calcium is 360. I'm a Reef Crystals fan.

 

I usually kept my FOWLR at 1.020 to 1.021.

 

I guess I'm going to go against the grain alone. lol

I've always ran my tanks at 1.025 - 1.026. Just seems more natural to keep it the same as the ocean where the fish come from. I do agree that it's harmless to keep it a bit lower, as long as you're sure you'll never want corals or inverts, but I have serious doubts about actual benefits. I've heard plenty of "reasons" why the SG *should* be lower for FO tanks, but I've yet to see any true scientific evidence to support any of those claims.

FWIW, IO was not specifically designed for reef tanks (hence the reason they developed RC), so the alk, cal, and mag are not elevated. Also, when you mix at a lower SG, all components will be proportionately lower.