Top off lowered salinity

[jdivz87]

Posted earlier about evaporation. Topped off in sump with freshwater and my salinity dropped. I was told not to add salt to that, but also get told to add salt directly in sump.

what should I do

 

[homer1475]

Water evaporates, salt doesn't. Always top off with fresh water.

 

[mrpontiac80]

When your water evaporates the salt stays behind and the salinity of the tank will increase.
top off with fresh rodi.
Is it possible you tested salinity just before you topped off and then afterwards it is lower?

 

[mrpontiac80]

Also, in my opinion I would never add salt to adjust salinity to a tank with livestock in it

 

[mdb_talon]

In general you should always be topping off with freshwater and it won't be lowering your longterm salinity. I mean if your salinity is 1.025 and it evap 5 gallons causing salinity to go to 1.026 then you add 5g freshwater you should see it back to 1.025..

Never add salt to the sump in my opinion. If for some reason your salinity is really too low than do topoff with mixed saltwater until your salinity is where you want then go back to topoff with fresh

 

[jdivz87]

I checked before 1.25 after evaporation.
Topped off freshwater… waited 2 hours checked salinity 1.22/23

 

[mdb_talon]

I checked before 1.25 after evaporation.
Topped off freshwater… waited 2 hours checked salinity 1.22/23

Yes that's going to happen if you are topping off large amounts at a time. You need to get salinity where you want it at the full mark....then topoff with freshwater. Anytime you add FW to saltwater it will lower the salinity a bit. However it should just be reducing the salinity that was slightly increased due to evap....keeping it stable overall. Topoffs should be small enough that you don't ever actually see the increase or decrease in salinity.

Don't wait so long to topoff. If your salinity readings are accurate that was a very large topoff relative to your tank size. Topoff more frequently so your salinity is not jumping up and.

 

[jdivz87]

Yes that's going to happen if you are topping off large amounts at a time. You need to get salinity where you want it at the full mark....then topoff with freshwater. Anytime you add FW to saltwater it will lower the salinity a bit. However it should just be reducing the salinity that was slightly increased due to evap....keeping it stable overall. Topoffs should be small enough that you don't ever actually see the increase or decrease in salinity.

Don't wait so long to topoff. If your salinity readings are accurate that was a very large topoff relative to your tank size. Topoff more frequently so your salinity is not jumping up and.

Makes a lot of sense!!! So you say once I notice salinity decrease…get it to where it should be then add freshwater?

 

[mdb_talon]

If your tank/sump is at the full mark and your salinity is 1.022 then yes I would just topoff with saltwater for the next few days/weeks it takes to get it to where you want. Once salinity is where you want then start using fw to topoff and it should stay there and rarely ever need adjustment.

 

[jdivz87]

If your tank/sump is at the full mark and your salinity is 1.022 then yes I would just topoff with saltwater for the next few days/weeks it takes to get it to where you want. Once salinity is where you want then start using fw to topoff and it should stay there and rarely ever need adjustment.

Got it!!!! Thank you for this

 

[Floyd-]

only add in RODI water for top off.
Never add salt directly to the tank (or sump) mix a batch of water and use that to bring up salinity.

 

[jdivz87]

Okay I don’t have RODI water unless there’s a DIY way to do it lol which I asked previously but I mixed in a bucket got salinity where I wanted them dumped