Salinity

Not an emergency anymore. I lost my last clown. My salinity was getting high due to evaporation so I topped off with ro/di water, salinity was at 1.032 so over 3 day duration I got it down to 1.024. Soon after, the clown started to not look so good, all other params look good. So I thought I'd bring the salinty back up to about 1.026 again very slowly, next day clown gone. So now I'm just trying to figure out where to keep the salinity to keep everyone happy or are clowns just that tempermental to any change. BTW everything else in the tank is doing well.
I spend almost everyday out at the reef in Key West, I'm a dive instructor and I have been checking salinity at about 5 miles out, 30 feet down everyday for the past week and it has been right at 40 ppt or 1.030, I thought it would have been lower. Just thought I'd share this info with ya. I'm going to keep my tank at 1.028 and see how it goes. Sorry for the long post.

 

1.023-1.025 with a cheapy hydrometer...bet you have the good eq doncha sorry and karma for your loss!

 

the sudden change did more harm then the level

 

Get a refractometer instead of using that swing arm hyro, it will be more accurate. If you get a bubble or not cleaned well that hyro will not give you accurate readings.

Premium Blue Refractometer - RHS-10ATC: Premium Aquatics

 

Just a thought,
1. are you using a swing arm hydrometer?
2. if yes, are you checking the water while you're AT depth? If so, could be the pressure down there is perhaps affecting the swing of the instrument??

I wouldn't be surprised if a swing arm device yields one reading at 30', and another at zero atmospheres. This might not be the case, but just a though.

I could have sworn reading somewhere that there's not that much fluctuation in the salinity of all the earth's seas. NSW is supposed to be 1.025.

 

Yup, I'm using a swing arm and finding out not too accurate.
And it doesn't work at depth, we fill a container at 30' and it consistantly comes up 1.028-1.030. Also the sea buoys off shore are reading anywhere between 1.026-1.030. I'm just thinking I brought it down too low(below 1.024) So based on the info I'm going to try and keep it at about 1.026 and see how it goes.

From the top of the ocean all the way to the depths of the ocean, salinity is between ~33-37 ppt or psu (average salinity of the ocean is 35 ppt).

 

I also have the refractometer Otty mentioned, so does Kogle, it works great, very well worth the money when you consider the price of lost livestock!! Sorry to hear about your clown, I can't believe it died!! My 2 lasted through the spikes in my cycle just fine, didn't act funny at all! In general they are VERY hardy fish.
Sorry again for the loss!!

 

I believe that temp. also plays a role on the salt level. The temp at 30ft down isnt the same when you bring it up to the surface. I also use the swing arm meter and have had it for almost two decades. I really dont know how accurate it is, but its been good to me so far.

 

yup, sure does.

bring an empty jar with a rubber tight sealed lid. open it under water to let the air out, or water. also bring a thermostat with ya. when you get back to land get the water back to the temp it was where you collected it and use a refractometer. i use a floating hydrometer calibrated at 77 degrees that works just fine for me. the only problem is its glass and you have to be carefull

its no where near accurate, youd be better off sticking your finger in the water and tasting it

at a depth of 30ft the atmospheric pressure is 2 and will give a different reading say if you were in colorado where its 1 mile above sea level. most people think hydrostatic pressure doesnt play a part, but it does.

 

Temperature and SG are directly related. Here is a calculator that you can use to measure correction of for temperature...

http://www.deltaenvironmental.com.au/management/Lab_methods/hydrometer_correction.xls