Checking salinity for FW

[wlepse]

I have a 37g tank that the wife wants to add mollies to once it is completely cycled. Since our LFS is Petco and they use aquarium salt in all their FW tanks we have been using it too but I don't know if I have a good level or not. I have followed the instructions but with frequent water changes I am wondering if the level is still correct. If I got a meter designed to read the specific gravity for salt water aquariums would it have enough resolution to measure relatively low levels of salt? What would you recommend I use and how frequently should I be checking this? My guess is I should do it weekly since I read the salt levels can affect the bio filter.

[Amazon]

You cant check for salt in freshwater:scratchheadyellow:

Mollys can livein pure saltwater so dont worry if you have to much. There is no instrument commercially available that I know of to do this. if you followed the directions it should all be fine.

[jaysee]

Another thing to keep in mind is as the water evaporates, the salt is left behind. I don't use salt, but I think you may want to be using marine salt??

[Northernguy]

Be careful not to add too much salt.Your filter does nothing to get rid of it.
The omnly way to removesalt is through gravel vacs and water changes.
Salt is really not neccisary in your tank.
Many lfs employees have the wrong idea about salt!
Please read this.
[Only Registered Users Can See Links.]

[Lab_Rat]

Agree that aquarium salt in freshwater is not necessary. I would not use it unless I was treating some particular issue.

[rich311k]

Mollys like hard water. They do not need salt or brackish conditions. Some crushed coral in your filter would keep them quite happy and feed them their veggies.