What can bring the Salinity down?
- Thread starter Ace1
- Start date
zeppelin
www.corareef.org
Addressing the title of your thread.
You should be topping off with RO freshwater, not saltwater.
When evaporation takes place, water is evaporated, but the salt is not, which will raise the tank salinity level. That raise will depend on your tank size(water volume) and the amount of evaporation per day you are getting. Topping off with saltwater, while replacing the evaporated water, also adds salt and increases the salinity. Hope I am making sense.
Topping off with a higher salinity water is actually increasing the issue. While that topoff saltwater will dilute into the tank water, and make the overall salinity level less than that of the topoff water you put in, your salinity level will still creep up over time as you are increasing the salinity of the tank a little everytime you add more saltwater.
The only time to add saltwater is when you do a water change, as you are then actually pulling the water and all its chemicals and minerals out at the same time, including salt.
Also, if you are adding topoff with a higher salt content as a means of raising your salinity on purpose because it is low, do that carefully, and preferably in the sump, away from any corals.
Salt level should remain constant in a tank unless there is a leak, and you have an RO freshwater auto topoff. In that case saltwater is leaking out and freshwater is being replaced, which would lower your salinity over time.
Hope this helps.
Larry
You should be topping off with RO freshwater, not saltwater.
When evaporation takes place, water is evaporated, but the salt is not, which will raise the tank salinity level. That raise will depend on your tank size(water volume) and the amount of evaporation per day you are getting. Topping off with saltwater, while replacing the evaporated water, also adds salt and increases the salinity. Hope I am making sense.
Topping off with a higher salinity water is actually increasing the issue. While that topoff saltwater will dilute into the tank water, and make the overall salinity level less than that of the topoff water you put in, your salinity level will still creep up over time as you are increasing the salinity of the tank a little everytime you add more saltwater.
The only time to add saltwater is when you do a water change, as you are then actually pulling the water and all its chemicals and minerals out at the same time, including salt.
Also, if you are adding topoff with a higher salt content as a means of raising your salinity on purpose because it is low, do that carefully, and preferably in the sump, away from any corals.
Salt level should remain constant in a tank unless there is a leak, and you have an RO freshwater auto topoff. In that case saltwater is leaking out and freshwater is being replaced, which would lower your salinity over time.
Hope this helps.
Larry
Last edited:
drummereef
Team RC
Use this to calibrate your refractometer and check back. 
Reef Aquarium Salinity: Homemade Calibration Standards
http://reefkeeping.com/issues/2004-06/rhf/index.htm
Reef Aquarium Salinity: Homemade Calibration Standards
http://reefkeeping.com/issues/2004-06/rhf/index.htm
Hypertek99
In Memoriam
If you are trying to bring it up then add more salt to your topoff if you are trying to bring it down then just add fresh water.
zeppelin
www.corareef.org
If topping off with R/O freshwater is lowering your salinity, then you have to have a leak somewhere. Saltwater is leaving your system, and being replaced with freshwater. Thats really the only reason I can come up with for the salinity level continually decreasing. Sorry I couldn't be of more help.
Hypertek99
In Memoriam
I think your refractometer is broken. Try a cheap swingarm one.
Malum Argenteum
Member
Salt leaves the system via skimmate, too.
lpsluver
New member
If his RSM skimmer is producing that much skimmate then it woud be a first for that skimmer. These skimmers are notorious for how ineffective they are, at the moment.
Just "field" calibrate the refractometer with RO water (resets to 1). This should be good enough to give you an idea. Swing arm hydrometers suck and can provide you with enough bad information to make things even worse.
seapug
Premium Member
Something is wrong with your refractometer. It is physically impossible to top off with saltwater and get a lower salinity reading unless you have stalactites of salt creep around your tank.
Get a cheap swing arm, get the Salinity where you want it, then, to make your life easier, make some sort of waterline mark and top off with FRESH water as needed to keep the water level at that mark. After that you can put the hydrometer in storage. I don't even use mine when mixing saltwater anymore.
Get a cheap swing arm, get the Salinity where you want it, then, to make your life easier, make some sort of waterline mark and top off with FRESH water as needed to keep the water level at that mark. After that you can put the hydrometer in storage. I don't even use mine when mixing saltwater anymore.
