Salinity

[andrew1986]

I recently set up a marine tank again and could not find my refractometer so i used my hydrometer to get the right salinity. Now that my new refractometer has arrived i have done a test and guess what to high. It is reading at 1.035 . what would be my best course of action? i know i need to add straight ro water but how much should i add per day cos i don't wanna change the salinity too fast so far I've been removing 1 pint from the tank and adding 1 pint of fresh ro by dripping it in. would this be safe or can i add it faster because it has taken me 2 days to get it to come down to 1.032

sorry about the wall of text was never any good in english lessons

 

[StandbySetting]

Did you calibrate the refractometer with RO water?

Just bring it down slowly, over a period of 12 or so hours will be fine.

 

[andrew1986]

yeah calibrated with ro water . is that right or should it be calibrated with something else ?

 

[StandbySetting]

RO water is fine.

 

[andrew1986]

ok thanks very much i shall add it a little faster then thanks for your help

 

[SaltNoob]

I have heard different opinions reading different forums on this subject of Calibrating with RO water. Some people are saying that RO is BAD to use with calibration and to not calibrate with it. Reading several "how to"'s they tell you to use basic, distilled water.

I calibrated mine two days ago with RO and am getting a reading in my tank of 1.027. I am interested to see if there is a difference with distilled. I will be getting some from the market this afternoon to check it out.

Also on the subject of salinity, what do most reefers run? Everything in my tank (will be in), when looked up on line, says about 1.020-1.025 so I am paranoid that this might be too high? I was hoping to just run at 1.025 as I have learned the corals/anems I want typically like a 1.026ish.

Thanks!

-Tyler

 

[StandbySetting]

Distilled water is the same as RO pretty much, it depends on how old the RO filter is, distilled water is likely to have a lower TDS than RO water if the RO membrane is old.

I used to run my system at about 1.025-1.026, you have to remember, your equipment is calibrated for use at 25[sup]o[/sup]C, so your calibration fluid should be at 25[sup]o[/sup]C when you calibrate the unit.

 

[SaltNoob]

The instructions in the box tell you to put the drops on the glass, then wait 30 seconds to allow the water to be similar in temperature. I can not imagine it taking long for the temp to adjust being only a few drops either.

One question though, when dropping water from the tank on the glass, should I be reading it immediately so it is the temp of the tank? OR wait for the tank water to cool down to the device?

-Tyler

 

[StandbySetting]

As long as you remain consistent that is all that matters, not measuring at 25oC means there will be ever so slight differences, but if you carry all readings out when the sample is at room temperature then you should have no issues providing you calibrate at room temperature as well.