What salinity level(s) do you run in your FOWLR?

[DaddyFish]

I'm thinking some data collection threads might be helpful?
You may or may not have a true FOWLR. Perhaps you have some corals too. Please explain your answer(s) in the thread.

 

[DaddyFish]

I am currently running one true FOWLR tank at 1.020 and one Hybrid tank (some corals) at 1.026.

 

[Apeman]

1.022

 

[Squidward]

1.022 - 1.023 ... I have some ricordia and few shrooms and some struggling leather.

 

[ReefHomieJon]

Why so low on the FOWLR tanks guys? Parasites and sickness at higher salinity?

 

[WRB]

1.019-1.021

 

[-XENOMORPH-]

Why so low on the FOWLR tanks guys? Parasites and sickness at higher salinity?

Marine tanks containing only fish and live rock (FOWLR) can be kept at a lower salinity level of 1.020-1.025 (SG), some hobbyists claim the lower salinity helps the fishes' osmotic regulation (less pressure on removing salt from the body) and marine parasites cannot thrive in lower salinity levels.

 

[kados]

1.020 for my FOWLRs. Anything more is a waste of salt and $ since no corals. LFS goes 1.019

 

[Oberst Hajj]

I've been keeping mine at 1.026 as that is the salinity that @tsmaquatics keep their fish at (they are the only place I buy fish from). That makes for a simple and less stressful transition for the fish. Once I'm done stocking it completely, I will probably lower it some.

 

[dyno]

Keep my fish at 20ppt. Much lower than anyone seems. Fish are pristine at this sg!

 

[Fishnut]

1.019

 

[JumboShrimp]

I got this Saddleback Clown home from the LFS— they had him swimming around at 1.029! I got a spare tank up to 1.028 and brought him down slowly during a week of observation, before putting him in an acclimation box in my DT... at 1.021.

 

[Ritchie G]

Does anyone know of any articles or studies on what Salinity is best for fish only? I am setting up a tank in a few months and i am thinking from what i read to keep it around 1.020, but i want to do as much research as i can before deciding on the salinity. Thanks

 

[DaddyFish]

Does anyone know of any articles or studies on what Salinity is best for fish only? I am setting up a tank in a few months and i am thinking from what i read to keep it around 1.020, but i want to do as much research as i can before deciding on the salinity. Thanks

@Jay Hemdal could answer...

 

[Jay Hemdal Verified Community Expert]

Does anyone know of any articles or studies on what Salinity is best for fish only? I am setting up a tank in a few months and i am thinking from what i read to keep it around 1.020, but i want to do as much research as i can before deciding on the salinity. Thanks

There is no best single value, it is rather, a range and that range can be different for different species.

The first thing to do is ensure you have an accurate means to measure salinity. Then, understand that there is some confusion between salinity and specific gravity, as the latter has a temperature component to it that needs to be accounted for.

That all said, for most coral reef fishes, I prefer a specific gravity of around 1.021, or a salinity of around 28 ppt. This saves a bit on salt costs, and allows for slightly reduced osmotic stress in the fish. However, many people set up "fish only" tanks and then add snails and other invertebrates, this changes the definition then (grin). Sharks and rays do better in full strength seawater.

Jay

 

[whybenormal]

I was doing a much lower specific gravity in my tank, around 1.020 - 1.021 until I added my tuxedo urchin. Everything I read said he would be much happier with it back at 1.025, so back up it went.

 

[Azedenkae]

Does anyone know of any articles or studies on what Salinity is best for fish only? I am setting up a tank in a few months and i am thinking from what i read to keep it around 1.020, but i want to do as much research as i can before deciding on the salinity. Thanks

There's quite a lot of research on the effect of salinity on (marine) fish growth and survival, just they are kinda at different points in the lifecycle and I can't find yet anything that is broadly applicable to all fish. There may of course be multiple variables that can in reality affect the fish differently or that affect different aspects of a fish' health differently.

Here for example, is an article that says survival of clarkii clownfish to be highest at 15 psu salinity: https://en.cnki.com.cn/Article_en/CJFDTotal-AHNY200901072.htm. 15 psu is around 1.011 sg if I am not mistaken. Unfortunately I can't actually download the full article to fully know how the study was done.

 

[Floyd-]

1.025 because my mixed reef tank is at 1.025 and I mix the water for the water changes at the same time and dont want to do two batches.