Salinity is not rising?

[Huenemedoe]

Hello Everyone!

So a week ago I realized my ATC refractometer was calibrated wrong by about .003. No big whoop, instead of being at 1.025 my tank was at 1.021 where it was running stable. I did a PWC of about 30%, brought the water up to 1.022 and figured I would just do some manual saltwater top offs with the rest of the 1.022 water that I had left over. The problem I am having is it's been 6 days of saltwater top offs and my Salinity has not changed. I have been calibrating my refractometer every day with RO just to be double sure, it's sometimes off a smidge (.0003ish very small amount) so I dial it in but am still getting the same results. Has anyone experienced this before? I also decided to just return to topping off with RO until I my new refract comes in a couple days or I get some answers.

Thanks Everybody!

 

[Larry L]

You will probably get more accurate results if you calibrate your refractometer with a salinity standard that's close to the specific gravity that you want to be at. Make sure you use a standard made for refractometers and not one made for conductivity meters.

 

[Waterislife]

Use distilled water to calibrate

 

[Larry L]

Use distilled water to calibrate

There are good reasons to calibrate using a solution that is close to the salinity you want to be at, more info here:

http://reefkeeping.com/issues/2006-12/rhf/#20

 

[jsker]

Distilled water would be good, but even better is to use a calibration solution that one can purchase. Then you would have a zero reading and an actual reading with the solution.

 

[lapin]

I did a PWC of about 30%, brought the water up to 1.022 and figured I would just do some manual saltwater top offs with the rest of the 1.022 water that I had left over.

If you are topping off with 1.022 water and your tank is at 1.022 its going to take a long time to register a change unless you have a ton of evaporation.

 

[Randy Holmes-Farley]

You will have to replace 14% of the tank water via evaporation and replacement with sg = 1.022 to rise from 1.022 to 1.025.

 

[Huenemedoe]

Thanks Everyone!

I did not think it would take that long for it to rise with SW top offs at the same salinity, really good to hear that, I always wrongly assumed it changed faster. I think the plan for now is to keep the slow increases, get some calibration fluid and then stabilize at 1.023. Every thing in my tank has been doing really well so not a lot of big desire to go all the way to 1.025.

Thanks again!