What range do you keep your salinity in?

I have always kept mine around 30 PPT (roughly 1.022 SG). As I was studying for finals, I realized that the average salinity of the ocean is about 34.7 PPT, which is out of the "safe range" on my hydrometer. Does (or has) anyone kept their salinity as high as 34.7 PPT? If so, what were the ramifications fof doing so?

 

i keep mine around 1.26 sg but I would think that keeping your salinity as high as the oceans may be a little more difficult and also the ocean water has alot of other things in it and possibly making it harder to maintain a tank with that level,I would also think that it definetly has been done just not by very mainy hobbists

 

1.026 SG is about 35 PPT, which is about average ocean salinity. But keep in mind, it is a range from about 31 PPT to about 38 PPT (hence the average of 34.7). I think sampling the average salinity of reef water would be a better measuring stick seeing as how density changes with temperature and depth.

The components of seawater doesn't change proportionally to each other (just in percentage to water).

Outside of Chloride and Sodium, you will find trace ions of Sufate, magnesium, Calcium, Potassium and Bicarbonate. All of these account for 99.9377% of the components of seawater. I believe all of these are present in the slat mixtures that you buy form your LFS.

 

I run mine between 34 and 36 ppt.

 

Part of it will depend on what you want to keep in your tank. Some invertebrates and most all corals will want it to be higher. If your planning and/or have corals I would shoot for 1.025. Many invertebrates and corals incorporate the water as part of their being so it's certainly something to pay close attention to.

 

I think ramifications of keeping a coral at natural salinity is that it will be happy

Really corals are quite sensitive to salinity. Their mortality is show to increase significantly with as little as a 10% change from their natural salinity. While salinity in various areas do vary a bit, 35ppt is about the average what we should try to keep it at as we do not tend to have information about where specific corals came from. 1.022 is too low, that is about 16% and long term will almost certainly be detrimental to at least some, if not most corals.

Another issue with lower salinity is your ca, alk, mg and trace elements will also be proportionally lower.
I think anywhere from 1.024 to 1.028 is generally fine though. Some people believe fish are better off at lower salinity. This is speculation, but salinity with regards to corals is not speculation, there is actually a fair amount of research.

 

Thanks guys. I have always gone off the hydrometer "safe-range" instead of actually researching it.

 

Also though, to add, hydrometers are not accurate. You should really invest in a refractometer and some 35ppt calibration fluid. You can get one for around $50 and is one of the most important things you can buy for your tank :thumb_up:

Edit: Also, make sure to get one with automatic temperature compensation. Other than that most are quite good, so spending extra probably isn't necessary.

 

I just got a refractometer yesterday and my life is so much simpler now. I know exactly what the salinity is, and now I actually have the ability to keep it where it should be. Before I was basically guessing, I don't mean to hijack the thread but salinity is very important and having a refractometer is the only way to go. Take it from me, someone who put off buying one for 6 months.

 

I keep mine between 1.025-1.026.