Specific Gravity::What SG level do you target and why??

I probably wasn't clear. Hit the link to my blog entry to see my consolidated write up for SG. From what I've read, most folks use a refractometer.

 

Refractometers are the ONLY way IMO.
Hydrometers are just too unreliable and notoriously out of calibration, or drift off calibration over time. You can get by with them, and lots of people do but it's too much hassle for me.

Good article, covers the basics. There are some other things to look for though.
Additional things that affect salinity.

Using 2 part calcium/alkalinity supplements will slowly raise SG over time from the byproducts (sodium and chloride ions) of the chemicals added. I don't think most people notice this if you do enough water changes but it's something to watch for, especially if you have a heavily stocked tank.

Also a drop in salinity could be from a slow leak from the tank or plumbing. You would not notice any levels changing, just possibly a puddle, but you may not even see a puddle as it may be evaporating. Excess salt creep around plumbing joints/bulkheads etc may be a good indicator though.

Also keep an eye on your calibration solution for the refractometer. Over time it can evaporate a little bit if you're not careful to reseal it immediately after use, or if you somehow contaminate it slowly over time with a dropper or whatever.

 

1.025

 

Screwtape, good additions. I added them as a comment on my blog to capture them.

Thanks
Mark