Amount of coral pro salt needed?

[Joining the reef]

Hey everyone, been out of the hobby a little and upon getting back in and filling my tank I thought half cup coral pro salt per gallon was the rule of thumb, but 8 gallons of water and 4 cups later I checked salinity an 1.016. I calibrated refractometer with RODI water before and a double checked it. Is this normal with this salt or should I just add more to the batch? Also I only let it mix about 2 hours not sure if that matters. Thanks in advance.

[MainelyReefer]

When I mix 4 gallons I am adding 1 1/2 cups of Red Sea Coral Pro.  I always test salinity though but over time have gotten the measuring by eye pretty close.  Add more salt

[Joining the reef]

Will do, just seemed like much if I needed to add more, guess refractometer won't lie though as long as it was calibrated 

[5*Chris]

I usually do 1/2 cup per gallon, but if I do like four gallons, than two of those half cups are heaping half cups and other two are leveled off exact. I like to mix a little high, I think it's easier to add water to drop than it is to add salt to raise salinity.

[Couesfanatic]

It's a little more than half a cup per gallon. I've noticed the same thing.

[mcarroll]

 

23 hours ago, 5*Chris said:

I usually do 1/2 cup per gallon, but if I do like four gallons, than two of those half cups are heaping half cups and other two are leveled off exact. I like to mix a little high, I think it's easier to add water to drop than it is to add salt to raise salinity.

Shouldn't be hard (with practice) to nail your targer s.g. pretty exactly "straight out of the bucket" if you want to. 

 

But I know what you mean about adjusting down being easier....I can vary the amount of water I take out of the tank to let the ATO make up the difference with pretty good accuracy if the water change water ends up "too thick" or (more likely) if the tank's salinity has crept up due to dosing two-part.

[Daniel-J]

I also do 1/2 per gallon.

[wiigelec]

Rodi will only verify the refractometer zero point you still need a calibration fluid to check the span if you haven’t done this your refractometer could be reading incorrectly...