Randy: Low salinity vs temp for fish oxygen

[Miami Reef]

I remember there was a post about someone saying that lower salinity is good for oxygen. Randy add claims about how salinity has little effect on oxygen and that lower temps were much better at increasing oxygen.

Randy also said that there’s no reason to think LFS use lower salinity for any reason other than saving cost.

He also said, “Oh, so fish are slowly suffocating in the sea…”

Im trying to give someone evidence how lower salinity doesn’t increase oxygen by much, but I can’t find that discussion thread.

Can you explain the evidence on how lower salinity doesnt really do much besides for saving cost? Thanks.

 

[Stigigemla]

A lower salinity will slow down the spread of some common parasites.
I have bought fish that was coming in 1,8% salinity with no problem but my main source today send fish in 3,0%
The invertebrates always arrive in 3,5%.
The problem with low salinity in transport in shops and transport is that You have to accomodate the fish to the normal salinity in the tank. From 3,0 to 3,5% from the shop You can do a drip water change in a bucket.

In my case I always adjust the salinity in the quarantine to the same as in the transport bags and then raise the salinity.
Usually in 8 days by adding salt to the sump a few times a day.

 

[Randy Holmes-Farley Verified Community Expert]

Here's a graph that shows both the effects together on O2:

graph_oxygen_concentration_vs.png

Figure1. Dissolved oxygen (ml/L, or ppm) solubility (maximum expected concentration) in waters of different salinity (parts per thousand). Seawater typically has a salinity of 35 parts per thousand, ...

serc.carleton.edu

 

[Malcontent]

Wow, check out the elevation effect too:

DO ⇆ %Saturation Calculator

www.waterontheweb.org

100% saturation is 6.67 mg/L in Denver but 8.26 at sea level.

 

[Randy Holmes-Farley Verified Community Expert]

Wow, check out the elevation effect too:

DO ⇆ %Saturation Calculator

www.waterontheweb.org

100% saturation is 6.67 mg/L in Denver but 8.26 at sea level.

Yes, elevation effect is big.

So is adding pure O2 into a shipping bag.