Salinity... Is 35 too high?

SereneAquatic

New member
We set up our tank to what we thought was the recommended amount of salinity. (Testing at 35 on the refractometer) but when we picked up our fish at the store, we gave them a water sample and they were surprised that we were keeping it that 'high'.

What level do most keep for a FOWLR tank? Is it unusual to maintain at that level?

Sent from my SM-G950U using Tapatalk
 
I would shoot for 24-25. Honestly the "watery" side is safer than than too salty.
I keep my reef at 20-21 because i am trying to breed clowns. No issues with inverts or corals and it gives me a buffer against evaporation. Lol sometimes i get behind on top off or the ato on my tank stops pumping correctly, keeping it low has saved my tank when I've been on vacation.
 
We set up our tank to what we thought was the recommended amount of salinity. (Testing at 35 on the refractometer) but when we picked up our fish at the store, we gave them a water sample and they were surprised that we were keeping it that 'high'.

What level do most keep for a FOWLR tank? Is it unusual to maintain at that level?

Sent from my SM-G950U using Tapatalk

Some clarity... at 35 as you stated, I would assume you are taking PPT (parts per thousand) the right side of the scale on a refractometer, where as the two replies gave you Specific Gravity. They are NOT the same scale.
1.021 Sg = 27.898 ppt This range is good for a FOWLR
1.024 Sg = 31.867 ppt

35 ppt = 1.0264 Sg Closer to natural sea water

You must be sure what scale you are referring to, as this is why people get in trouble! Apples do not equal Oranges!

Salinity Conversion Calculator
https://www.hamzasreef.com/Contents/Calculators/SalinityConversion.php
 
Some clarity... at 35 as you stated, I would assume you are taking PPT (parts per thousand) the right side of the scale on a refractometer, where as the two replies gave you Specific Gravity. They are NOT the same scale.
1.021 Sg = 27.898 ppt This range is good for a FOWLR
1.024 Sg = 31.867 ppt

35 ppt = 1.0264 Sg Closer to natural sea water

You must be sure what scale you are referring to, as this is why people get in trouble! Apples do not equal Oranges!

Salinity Conversion Calculator
https://www.hamzasreef.com/Contents/Calculators/SalinityConversion.php
Yes thank you. I am looking at PPT. Is there a reason that the natural sea water level is not what you want in a tank? Aren't most fish wild caught?

Sent from my SM-G950U using Tapatalk
 
There is nothing wrong with keeping a FOWLR at 35 ppt, it's just not necessary. Fish actually will do better at a slightly lower salinity, even though that may seem counterintuitive. I alway ran mine at about 29.
 
In a reef tank setup ie soft corals, but more so lps & sps, you would like to keep the salinity level as close to NSW as possible.
But typically in a FOWLR, people tend to run them lower which helps reduce parasitic diseases.
My LFS keeps his sell tanks around 1.018 sg or 23.921 ppt for this very reason.
 
Some clarity... at 35 as you stated, I would assume you are taking PPT (parts per thousand) the right side of the scale on a refractometer, where as the two replies gave you Specific Gravity. They are NOT the same scale.
1.021 Sg = 27.898 ppt This range is good for a FOWLR
1.024 Sg = 31.867 ppt

35 ppt = 1.0264 Sg Closer to natural sea water

You must be sure what scale you are referring to, as this is why people get in trouble! Apples do not equal Oranges!

Salinity Conversion Calculator
https://www.hamzasreef.com/Contents/Calculators/SalinityConversion.php
Oh heck, thank you sir! My bad op!
 
Fish only do better in lower SG because it is easier for them to breath.
35 is NSW and is what we use in a mixed reef.
32 SG is great for fish..
 
Fish only do better in lower SG because it is easier for them to breath.
35 is NSW and is what we use in a mixed reef.
32 SG is great for fish..

If you’re saying 32 SG is great for fish they will be floating in no time!
Read my first post about SG vs PPT
Two very different measurements of salinity.
 
Last edited:
Although, I kept two clowns in 1.035 SG for a year in a 20g while I was moving and didn't notice my old refractometer was not calibrated correctly.
Man...they were so happy when I finally calibrated and lowered to 1.025, the were supercharged for days....
 
also be aware that with lower salinity there might be a need to re-adjust your skimmer. depending on how low you go. i have seen tanks ran at 1.021/1.022 and they were gradually bumped up to 1.025 or so and the skimmers internal water level needed to be lowered.

corey
 
Back
Top