Mixed reef at low salinity?

[nanomania]

Is anyone keeping a mixed reef or a softies only or softies with lps at low salinity levels? Most of the hobbyists run at 1.026, iv kept softies at 1.023. Can we keep a reef between 1.020 to 1.023? Asking coz i feel its much better for fishes.

 

[Randy Holmes-Farley Verified Community Expert]

Why do you think it is better for fish? I've not seen evidence of this.

 

[nanomania]

Why do you think it is better for fish? I've not seen evidence of this.

Well iv read a few post where they mention that low salinity has more dissolved o2 and this increases immunity of the fish too. If thts really true.

 

[Randy Holmes-Farley Verified Community Expert]

Well iv read a few post where they mention that low salinity has more dissolved o2 and this increases immunity of the fish too. If thts really true.

It does have more O2, but they have evolved to live at 34-36 ppt (sg = 1.0256 to 1.0272) and while it is common practice to keep fish at lower salinity than the ocean, I've never seen evidence that fish are healthier or happier at lower salinity.

Here's my comment on salinity from one of my articles:

https://www.reef2reef.com/threads/o...-reef-aquarium-by-randy-holmes-farley.173563/

Salinity

There are a variety of different ways to measure and report salinity, including conductivity probes, refractometers, and hydrometers. They typically report values for specific gravity (which has no units) or salinity (in units of ppt or parts per thousand, roughly corresponding to the number of grams of dry salt in 1 kg of the water), although conductivity (in units of mS/cm, milliSiemens per centimeter) is sometimes used.

Somewhat surprisingly, aquarists do not always use units that naturally follow from their measurement technique (specific gravity for hydrometers, refractive index for refractometers, and conductivity for conductivity probes) but rather use the units interchangeably.

For reference, natural ocean water has an average salinity of about 35 ppt, corresponding to a specific gravity of about 1.0264 and a conductivity of 53 mS/cm. It often ranges from 34-36 ppt over reefs, but can be higher or lower locally for various reasons such as land run off of fresh water, or evaporation from a lagoon.

As far as I know, there is little real evidence that keeping a coral reef aquarium at anything other than natural levels is preferable. It appears to be common practice to keep marine fish, and in many cases reef aquaria, at somewhat lower than natural salinity levels. This practice stems, at least in part, from the belief that fish are less stressed at reduced salinity. I have no idea if that is true or not, but I’ve not seen evidence that it is true. Substantial misunderstandings have also arisen in the past among aquarists as to how specific gravity really relates to salinity and density, especially considering temperature effects. For example, the density of seawater is less than the specific gravity, and measurements with glass hydrometers may require temperature correction, but newer devices do not need the aquarist to make corrections. Consequently, older salinity or “specific gravity†recommendations may not actually be referring to the same measurements that aquarists make today, even if the recommended numbers have been handed down

My recommendation is to maintain salinity at a natural level. If the organisms in the aquarium are from brackish environments with lower salinity, or from the Red Sea with higher salinity, selecting something other than 35 ppt may make good sense. Otherwise, I suggest targeting a target salinity of 35 ppt (specific gravity = 1.0264; conductivity = 53 mS/cm).

 

[nanomania]

It does have more O2, but they have evolved to live at 34-36 ppt (sg = 1.0256 to 1.0272) and while it is common practice to keep fish at lower salinity than the ocean, I've never seen evidence that fish are healthier or happier at lower salinity.

Here's my comment on salinity from one of my articles:

https://www.reef2reef.com/threads/o...-reef-aquarium-by-randy-holmes-farley.173563/

Salinity

There are a variety of different ways to measure and report salinity, including conductivity probes, refractometers, and hydrometers. They typically report values for specific gravity (which has no units) or salinity (in units of ppt or parts per thousand, roughly corresponding to the number of grams of dry salt in 1 kg of the water), although conductivity (in units of mS/cm, milliSiemens per centimeter) is sometimes used.

Somewhat surprisingly, aquarists do not always use units that naturally follow from their measurement technique (specific gravity for hydrometers, refractive index for refractometers, and conductivity for conductivity probes) but rather use the units interchangeably.

For reference, natural ocean water has an average salinity of about 35 ppt, corresponding to a specific gravity of about 1.0264 and a conductivity of 53 mS/cm. It often ranges from 34-36 ppt over reefs, but can be higher or lower locally for various reasons such as land run off of fresh water, or evaporation from a lagoon.

As far as I know, there is little real evidence that keeping a coral reef aquarium at anything other than natural levels is preferable. It appears to be common practice to keep marine fish, and in many cases reef aquaria, at somewhat lower than natural salinity levels. This practice stems, at least in part, from the belief that fish are less stressed at reduced salinity. I have no idea if that is true or not, but I’ve not seen evidence that it is true. Substantial misunderstandings have also arisen in the past among aquarists as to how specific gravity really relates to salinity and density, especially considering temperature effects. For example, the density of seawater is less than the specific gravity, and measurements with glass hydrometers may require temperature correction, but newer devices do not need the aquarist to make corrections. Consequently, older salinity or “specific gravity†recommendations may not actually be referring to the same measurements that aquarists make today, even if the recommended numbers have been handed down

My recommendation is to maintain salinity at a natural level. If the organisms in the aquarium are from brackish environments with lower salinity, or from the Red Sea with higher salinity, selecting something other than 35 ppt may make good sense. Otherwise, I suggest targeting a target salinity of 35 ppt (specific gravity = 1.0264; conductivity = 53 mS/cm).

So its never ok to keep salinity below 1.026? Iv kept my salinity at 1.024 in the past without any issues to corals and inverts.. so can i keep at 1.025? I find it easier to maintain at 1.024 and 25.

 

[Randy Holmes-Farley Verified Community Expert]

I don't believe I said it is not OK to keep reefs below 1.026. Most marine creatures are actually quite adaptable to higher or lower salinity, and we are very fortunate for that fact since many people have salinity quite different from what they think it is due to measurement problems. Many people keep reefs in the 1.023 to 1.025 range. I don't think that is preferable to matching natural levels, but if there is a reason or desire to do it, it seems to work OK.

 

[nano reef]

I know this is an old thread but I just found out my salinty is way lower then I thought! Who can afford to open a new pack of individual hanna checker solution ever time you check salinity? I may go back to the old fashion way but man its so easy to dip the stick in! Anyway Brock Leonard who does you tubes always suggest salinty between 1021 to 1023 I believe but I know way lower then the norm! I think most his videos are on fish though. Not to say he is an expert but always wondered why! Now I know why all my corals are dying except my softies! I am going to gradually up it! Anyone know of what is the right amount to up so that it dosnt shock the corals and fish?? Scary thing is Ijust got a new fish and 4 nudibranches today and not sure what to do. I havnt checked their salinity yet. Is it safe to up mine by maybe 2 points and how much lower can new fish acclimate at?

 

[Randy Holmes-Farley Verified Community Expert]

I know this is an old thread but I just found out my salinty is way lower then I thought! Who can afford to open a new pack of individual hanna checker solution ever time you check salinity? I may go back to the old fashion way but man its so easy to dip the stick in! Anyway Brock Leonard who does you tubes always suggest salinty between 1021 to 1023 I believe but I know way lower then the norm! I think most his videos are on fish though. Not to say he is an expert but always wondered why! Now I know why all my corals are dying except my softies! I am going to gradually up it! Anyone know of what is the right amount to up so that it dosnt shock the corals and fish?? Scary thing is Ijust got a new fish and 4 nudibranches today and not sure what to do. I havnt checked their salinity yet. Is it safe to up mine by maybe 2 points and how much lower can new fish acclimate at?

What is your salinity now?

Best way to slowly raise salinity is to replace evaporated water with salt water until you get to your target, unless it is below sg = 1.020, in which case you may need to go faster.

 

[Dburr1014]

Is anyone keeping a mixed reef or a softies only or softies with lps at low salinity levels? Most of the hobbyists run at 1.026, iv kept softies at 1.023. Can we keep a reef between 1.020 to 1.023? Asking coz i feel its much better for fishes.

I will say mine dipped to 1.021 over a coarse of a couple weeks. (doing a lot of testing and not watching the sg) and I had some sps bleaching. They recovered once I got it back up. So in my experience, below 1.022 definatly is not good. I try to stay constant at 1.026.