Ideal Salinity

[Hot2na]

For reference, natural ocean water has an average salinity of about 35 ppt, corresponding to a specific gravity of about 1.0264

Funny how things change : in the 70's & 80's instant ocean (aquarium systems) used to state something like - The salinity of the world's oceans is on average is- 1.023.....
I collect natural sea water for my tank off the coast of delaware, ...In all the yrs of collection and testing - I usually see close to 1.023...depending on when it rains, tide etc...I used to see similar results when I lived on the south shore of long island..

So how we now say 1.0264 is confusing ....

 

[Randy Holmes-Farley Verified Community Expert]

Funny how things change : in the 70's & 80's instant ocean (aquarium systems) used to state something like - The salinity of the world's oceans is on average is- 1.023.....
I collect natural sea water for my tank off the coast of delaware, ...In all the yrs of collection and testing - I usually see close to 1.023...depending on when it rains, tide etc...I used to see similar results when I lived on the south shore of long island..

So how we now say 1.0264 is confusing ....

lol

Actual oceanographers have known the average salinity was about 35 ppt (specific gravity = 1.0264; density = 1.0233) for more than a hundred years.

I personally suspect that some aquarists in the past got confused about the difference between specific gravity and density, and mistakenly attributed the density values around 1.023 to specific gravity.

 

[Hot2na]

I personally suspect that some aquarists in the past got confused about the difference between specific gravity and density, and mistakenly attributed the density values around 1.023 to specific gravity

Perhaps... when I collect NSW and it measures 1.023 I just warm it up and use it as is...If it's less -i'll aerate it and leave the top off the holding container until it's 1.023... Everything in my tank is thriving at that SG... One of my Gigantea anemones has tripled in size in a little over a yr...

 

[Randy Holmes-Farley Verified Community Expert]

Perhaps... when I collect NSW and it measures 1.023 I just warm it up and use it as is...If it's less -i'll aerate it and leave the top off the holding container until it's 1.023... Everything in my tank is thriving at that SG... One of my Gigantea anemones has tripled in size in a little over a yr...

Glad things are doing well! Aquaria seem not particularly sensitive to exact salinity. Salinity certainly varies in the ocean, and is often lower near shores due to rainwater runoff.

 

[MJ59HK]

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).

Sorry to bring up an old thread. Having read through the many posts on this topic, I would like to know if my NSW salinity I get from local suppliers is less than 35ppt (it is 32.9ppt) how do I bring it back up to 35ppt. Do I just add synthetic salt to bring it back up? If so, what is a recommended brand for this purpose?

 

[gibbers]

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).

Most through answer ever!! Thank you

 

[Randy Holmes-Farley Verified Community Expert]

Sorry to bring up an old thread. Having read through the many posts on this topic, I would like to know if my NSW salinity I get from local suppliers is less than 35ppt (it is 32.9ppt) how do I bring it back up to 35ppt. Do I just add synthetic salt to bring it back up? If so, what is a recommended brand for this purpose?

You could add salt, evaporate what you buy, use it as is by adding more than you remove in a water change, or lower the tank salinity level.
If it was my system, I’d opt for the add more than you remove, but I did very small and slow water changes by AWC.

Any decent salt mix is suitable for boosting the salinity.

 

[reefsaver]

Sorry to bring up an old thread. Having read through the many posts on this topic, I would like to know if my NSW salinity I get from local suppliers is less than 35ppt (it is 32.9ppt) how do I bring it back up to 35ppt. Do I just add synthetic salt to bring it back up? If so, what is a recommended brand for this purpose?

When starting out, choose a synthetic Reef Aquarium Salt you are sure you will be happy with for the life of the aquarium. It's generally advised to stick to one brand of Reef salt so choose wisely. I'd advise a brand that has multiple sizes of salt that seems high quality because you don't want to go changing at a later date so it's best to be happy with your choice at the start. The option to buy smaller packs of salt can help a lot in tough times. I would advise Aqua Forest Reef Salt because it's almost the standard reef salt Marine stores use themselves in the industry now days.

I'd say doing the research like you have done by being here is one of the first steps to being a highly successful beginner Reefer.
Choosing your salt is a big phase in the start of the hobby because it means you can make your own sea water at home. I would next think about investing in an RODI filter so you can make clean 0 TDS (Total Dissolved Solids) water, free of chorine, chloramines and other nasty minerals. Using rainwater through an RODI can significantly extend it's life.
And then you have the whole water side covered. You can then really focus on improving the stability of the Aquariums water chemistry by buying more testing and maintenance equipment as you go. And different hardware like Reactors (Reactor= A container that water flows through that you put media in, the simplest being Activated Carbon to remove toxins and significantly improve water quality even visually.)

 

[X-37B]

I target 1.0265 with my range of 1.026- 1.027. This has worked well for many years. Whatever you run stability is really more important than the level, to a certain degree.

 

[Randy Holmes-Farley Verified Community Expert]

I would advise Aqua Forest Reef Salt because it's almost the standard reef salt Marine stores use themselves in the industry now days.

How do you know that?

I personally wouldn't use choices of an LFS to impact my decisions of what is best since they often do things for cost reasons, and may not have a whole lot of other good reasons.

 

[X-37B]

When starting out, choose a synthetic Reef Aquarium Salt you are sure you will be happy with for the life of the aquarium. It's generally advised to stick to one brand of Reef salt so choose wisely. I'd advise a brand that has multiple sizes of salt that seems high quality because you don't want to go changing at a later date so it's best to be happy with your choice at the start. The option to buy smaller packs of salt can help a lot in tough times. I would advise Aqua Forest Reef Salt because it's almost the standard reef salt Marine stores use themselves in the industry now days.

I'd say doing the research like you have done by being here is one of the first steps to being a highly successful beginner Reefer.
Choosing your salt is a big phase in the start of the hobby because it means you can make your own sea water at home. I would next think about investing in an RODI filter so you can make clean 0 TDS (Total Dissolved Solids) water, free of chorine, chloramines and other nasty minerals. Using rainwater through an RODI can significantly extend it's life.
And then you have the whole water side covered. You can then really focus on improving the stability of the Aquariums water chemistry by buying more testing and maintenance equipment as you go. And different hardware like Reactors (Reactor= A container that water flows through that you put media in, the simplest being Activated Carbon to remove toxins and significantly improve water quality even visually.)

All the lfs stores I know use IO due to cost. Same with most public aquariums.

 

[reefsaver]

How do you know that?

I personally wouldn't use choices of an LFS to impact my decisions of what is best since they often do things for cost reasons, and may not have a whole lot of other good reasons.

I don't know it for fact it's pretty based but we use it at my work (AF Sea Salt) and BRStv advertises AF products as well as many other Reeftubers. I was taught when I started out that when I choose my salt, to choose one that my LFS uses too and know their parameters to mirror them, so as I purchase livestock in store they don't go through as much of a chemistry change or shock.
It's definitely true though that a shop would use a cost effective means of synthetic salt. It makes sense that we use AF Salt in our systems because we sell all versions of it to customers and purchase it in bulk. We also sell Red Sea.

 

[Randy Holmes-Farley Verified Community Expert]

I don't know it for fact it's pretty based but we use it at my work (AF Sea Salt) and BRStv advertises AF products as well as many other Reeftubers. I was taught when I started out that when I choose my salt, to choose one that my LFS uses too and know their parameters to mirror them, so as I purchase livestock in store they don't go through as much of a chemistry change or shock.
It's definitely true though that a shop would use a cost effective means of synthetic salt. It makes sense that we use AF Salt in our systems because we sell all versions of it to customers and purchase it in bulk. We also sell Red Sea.

Thanks.

I agree that if you can match your livestock supplier in salinity, that can make additions easier.

 

[CABIX_81]

1.025 for my mixed reef. Are you fish only?

Im a FO, and new to this, been for about 3months now, no corals at all, whats a spec fora a pair of clowns an a firefish with some clean up crew? Here is my parameters using api

 

[thatmanMIKEson]

What is your ideal salinity. My tank is at 79 degrees F and has a specific gravity of 1.022. I read in ppt that that equates 31.6 ppt salinity. What is the ideal range you guys have success with??

35ppt @78.5 +/- 1°

 

[FernBluffReef]

Returning to reefing a couple months ago. Tried a refractometer. What a waste of money. Good thing they only cost ~$40. I get a different reading each time I use pretty much, have to constantly re-calibrate, etc. etc.

Went and bought a $15 hydrometer and so happy I did and will never go back. The hydrometer is more accurate and reliable IMO, just have to know how to use it correctly. Readings are consistent every time. Muddling with refractometer confirms the hydrometer is reading correctly.

Running both tanks at 1.026 / 35ppt

 

[DaprDon]

Tropic Marin floating glass tube hydrometer is known to be the most accurate device. No calibration.
I have one and wasn't using it. I was using a calibrated refractometer and it said I was at 1.024. Started getting clear(white) slime for months. Took my water to be tested and was told it was 1.021. Got home and used the Tropic Marin hydrometer, it was at 1.021!
Recalibrated my refractometer with new calibration fluid and tested again. It came up 1.024. Obviously the refractometer is off. I've been slowly raising my salinity. Once it got over 1.023 my slime issues stopped. Low salinity was irritating my LPS and other corals. Waiting till it hits 1.026 before I turn ATO back on.

 

[Salty_Northerner]

Tropic Marin floating glass tube hydrometer is known to be the most accurate device. No calibration.
I have one and wasn't using it. I was using a calibrated refractometer and it said I was at 1.024. Started getting clear(white) slime for months. Took my water to be tested and was told it was 1.021. Got home and used the Tropic Marin hydrometer, it was at 1.021!
Recalibrated my refractometer with new calibration fluid and tested again. It came up 1.024. Obviously the refractometer is off. I've been slowly raising my salinity. Once it got over 1.023 my slime issues stopped. Low salinity was irritating my LPS and other corals. Waiting till it hits 1.026 before I turn ATO back on.

I had the same issue using refractometers and even calibration would show xxx I invested in a Tropic Marin analog hydrometer and wouldn't ever set up or maintain a tank again without one. I'll use the Hanna salinity conductivity checker and it's generally spot on but I'm using the Neptune fluid over the Hanna fluid since it matches the TM hydrometer.

 

[Randy Holmes-Farley Verified Community Expert]

Tropic Marin floating glass tube hydrometer is known to be the most accurate device. No calibration.
I have one and wasn't using it. I was using a calibrated refractometer and it said I was at 1.024. Started getting clear(white) slime for months. Took my water to be tested and was told it was 1.021. Got home and used the Tropic Marin hydrometer, it was at 1.021!
Recalibrated my refractometer with new calibration fluid and tested again. It came up 1.024. Obviously the refractometer is off. I've been slowly raising my salinity. Once it got over 1.023 my slime issues stopped. Low salinity was irritating my LPS and other corals. Waiting till it hits 1.026 before I turn ATO back on.

It may be among the more accurate devices hobbyists use, but it is hyperbole to claim it is the most accurate device.

I’d also add that a huge number of folks just assume it is accurate without ever actually testing theirs.