Reading Salinity

[twenty12]

I just setup my BioCube 29 and added salt. When I performed the first reading it was after several hours when the salt appeared to be dissolved. The reading was 1.030. About 24 hours later I read it again and it reads 1.020. The only difference is that it had longer to "mix" and I dropped the temp from 79 to 77. From what I can tell temp can affect the reading... but not by that much. So my quesiton is how long does it take salt to mix before you get an accurate reading, and or what factors could contribute to the different readings.
BTW: The first reading is likely the wrong one since I bout 35 gallons of salt mix and by estimate I put in about 25 gallons worth (which would coincide with the 1.020 reading).
Thanks!

 

[princess8077]

hrm....I thought you were suppose to mix the salt in a container and be sure it was dissolved before adding to the tank.

 

[twenty12]

Yes.. you are from my reading as well. But it was new tank and empty. Not a thing in it no sand, rocks, etc. So I figured I would add it to the tank directly. I added it over time so that it would not be a big dump of salt.

 

[lexluethar]

My assumption is you are using a hydrometer and they are EXTREMELY difficult to get a constant reading. I had one for a while, the water temperature effects the readings, air bubbles effect the readings, they are near worthless IMO when you consider how off they can be.
Spend 30 dollars and purchase a refractometer and you'll be extremely happy. When testing my SG with a hydrometer, for about two months my readings were rarely similar, but usually around 1.025 (where i wanted it). After purchasing a refractometer my reading was 1.018 - which isn't good. I continued to test for a few weeks thinking the hydrometer couldn't be that off - well it was, consistently off.
Sorry for the rant, i just think purchasing a ref. is worth the cost (sorry if your readings are with a ref.)

 

[calvertbill]

I agree with LexL. I bought a hydrometer when I first got started and after I started using the refractometer I tested with both for a while. Whereas the ref. was always consistant the hydro. kept throwing aberrant readings every so often. Trust me, the first time you need to hypo a sick fish you'll be glad you upgraded.

 

[snakeblitz33]

invest in a refractometer.

 

[matt b]

Originally Posted by SnakeBlitz33
invest in a refractometer.

 

[twenty12]

I have not seen any under $60 which is why I have not purchased one. Can anyone recommend a model or place to get one?

 

[sepulatian]

Google it. I wish this site still sold them. I bought mine for $40 and it came pre-calibrated.

 

[sepulatian]

Originally Posted by LexLuethar
When testing my SG with a hydrometer, for about two months my readings were rarely similar, but usually around 1.025 (where i wanted it). After purchasing a refractometer my reading was 1.018 - which isn't good.
I had used a hydrometer for awhile. My two tanks were 1.025 and 1.026. When I got the refractometer and tested I found out that they were actually 1.030 and 1.031 respectively. Hydrometers can be off in either direction.

 

[waterlogged]

Originally Posted by sepulatian
I had used a hydrometer for awhile. My two tanks were 1.025 and 1.026. When I got the refractometer and tested I found out that they were actually 1.030 and 1.031 respectively. Hydrometers can be off in either direction.
If you have a QT and DT should you have 2 for prevention of cross contamination?

 

[sepulatian]

Originally Posted by Waterlogged
If you have a QT and DT should you have 2 for prevention of cross contamination?
What do you mean?

 

[lexluethar]

Originally Posted by Waterlogged
If you have a QT and DT should you have 2 for prevention of cross contamination?
I believe he means when you use a hydrometer you are putting a lot of water in the unit - meaning if the water is contaminated that it could cary over into another tank. WIth a ref. this is minimal because you just use two drop on the lense of the ref. and it is very easy to clean.
In regards to a hydrometer, you are caring, what four or five shots glasses worth (you know you have a drinking problem when that is your unit of measurement) of water, and that water can carry a parasite.

 

[sepulatian]

Waterlogged has a refractometer. I have one refractometer and simply wipe the dropper after every use. But for a hydrometer the water gets dumped out each time. If one were to use the same instrument for two tanks, as I did when I was very new to salt, then to prevent cross contamination you would have to rinse it VERY thoroughly with fresh water.

 

[waterlogged]

Originally Posted by sepulatian
Waterlogged has a refractometer. I have one refractometer and simply wipe the dropper after every use. But for a hydrometer the water gets dumped out each time. If one were to use the same instrument for two tanks, as I did when I was very new to salt, then to prevent cross contamination you would have to rinse it VERY thoroughly with fresh water.
Sorry Sep, I am just paranoid about stopping ich because I have fought it for so long. I thought I had it beat a couple times with reef safe meds. only to find out a month later I was wrong. Ich is an epidimic and that is why my signature is QT or suffer. Oh how I have suffered.
Sorry if I got off thread subject.