1.024 or 1.026, what's your preference and why?

[SaltwaterGuruNeeded]

Which is a better overall salinity for fish, 1.024 or 1.026 and why?

 

[Gedxin]

What if I said 1.025?

 

[Jekyl]

35ppt. My coral prefer it.

 

[SaltwaterGuruNeeded]

What if I said 1.025?

Yeah, that could be an option. But debating whether 1.024 or 1.026 is better.

 

[Randy Holmes-Farley Verified Community Expert]

I doubt it matters, but 35 ppt (sg = 1.0264 ) is the worldwide ocean average.

If you used natural seawater and were at sg = 1.024, all of the major ions would be low (e.g., magneisum at 1164 ppm).

 

[SaltwaterGuruNeeded]

I doubt it matters, but 35 ppt (sg = 1.0264 ) is the worldwide ocean average.

If you used natural seawater and were at sg = 1.024, all of the major ions would be low (e.g., magneisum at 1164 ppm).

Lfs said that as salinity increase they have to breathe more often.

 

[Gtinnel]

I try to keep mine at 1.026 but occasionally it will dip down to 1.025. My assumption has always been that keep it stable is more important than the specific number.

 

[Screwgunner]

I run my water 1.024 with my swing arm . When I check it with my refractometer it comes out 1.026.

 

[Randy Holmes-Farley Verified Community Expert]

Lfs said that as salinity increase they have to breathe more often.

Yes, the fish in the ocean are slowly suffocating. lol

The tiny nugget of truth behind that claim is that O2 saturation is a teeny tiny bit higher at sg = 1.024 than at sg = 1.026. 6.89 mg/L O2 vs 6.79 mg/L O2.

That difference is very small, and there's no reason to assume the O2 is ever governed by the saturation level. It can be both higher (during the day ) and lower (at night).

LFS usually keep salinity lower because it is cheaper. Anything else (except hypo) is just an excuse, IMO.

 

[MaxTremors]

Which is a better overall salinity for fish, 1.024 or 1.026 and why?

1.026 or 35ppm, closer to natural seawater.

 

[Grey Guy]

Which is a better overall salinity for fish, 1.024 or 1.026 and why?

It is my understanding that the higher the salinity, the less oxygen is in the water. Great for corals, bad for fish. In the old days if you cared for your fish, it was common to keep salinity at 1.022.

 

[Screwgunner]

For fish only 1.020 1.024 reef tank 1.025 1.026

 

[husemn]

1.027.... My corals are happier there.

 

[Randy Holmes-Farley Verified Community Expert]

It is my understanding that the higher the salinity, the less oxygen is in the water. Great for corals, bad for fish. In the old days if you cared for your fish, it was common to keep salinity at 1.022.

Not so true, as I show above.

 

[arking_mark]

Which is a better overall salinity for fish, 1.024 or 1.026 and why?

Better question is how are you measuring it. :)

My hobby measuring tools don't do a great job (Hanna, GHL, Refractometer). I found this out and ended up crosschecking with a high-precision TM Hydrometer. Now I have confidence in my salinity and its at 1.0264 (automatically maintained through GHL).

 

[Randy Holmes-Farley Verified Community Expert]

Ocean acidification alters temperature and salinity preferences in larval fish​

https://link.springer.com/article/10.1007/s00442-016-3778-z
In this study, normal larval fish (Barramundi) showed a strong preference for 35 ppt (sg = 1.0264) compared to 25 ppt (sg = 1.019)

 

[jcosta98]

Keeping 1.026 because that's what my salt recommends

 

[a4edwin]

I’m at 1.025

 

[Ocean’s Piece]

1.026 because my calcium and alkalinity levels are closer to those in the reefs

 

[X-37B]

I would run as close to NSW as possible and do.
If it works in the ocean it will work in your tank, imo.