Salt for use in freshwater aquariums

[Lateral Line]

Specific Gravity - it is how marine aquarists measure their salt content.

 

[The-Wolf]

I've had a quick search for converting ppm to SG and I got confused to say the least.
I am in no way shape or form even going to attempt it.
any chemist that can help out here?

 

[Ed4567]

The-Wolf wow thats a question and a half...

Here is an article describing the relationship:
http/www.advancedaquarist.com/issues/jan2002/chemistry.htm

Bascially the specific gravity of a sample is a function of its salinity and its temperature.

 

[Ed4567]

And a table giving a few conversions about 1/5 of the wy down:

http/reefkeeping.com/issues/2004-06/rhf/index.htm

 

[The-Wolf]

Bascially the specific gravity of a sample is a function of its salinity and its temperature.

thats a basic description
is there an even more basic description, one that I can understand?
I doubt it.

 

[Ed4567]

Ok I'll try:

First of all density is a measure of how much stuff there is in a certain volume (=mass/volume)

- Suppose you have pure water, this has a particular density.
- You then dissolve some salt in the water. Since salt has a higher density than water the new mixture now has a higher density than the pure water.
- The more salt you add the higher the density of the mixture.

Specific gravity gives you a measure of the density of the mixture compared to the density of pure water, and so gives you a measure of the salinity of the water.

Unfortunatly temperature complicates things and for an explaination the article posted above would probably be the easiest source.

Hope this makes sense.

 

[_fish_a_holic_]

The reason I asked about specific gravity is, that's what my hydrometer reads. (it's one of those glass ones that have a thermometer on the bottom with a thinner glass tube SG scale on the top) You float it in the water and read off the water line where the SG is.

Are there others out there that read ppm???

 

[CTS]

What about salt and live plants i hear that they do not get along well is this correct or false?

 

[_fish_a_holic_]

Most live plants, as I understand it...

 

[pica_nuttalli]

BUMP

 

[stephend]

Yikes! That was frightening. I opted to add 1g/litre (about half the manufacturer's recommendation) to my tank to help knock some fungal infection on the head. Watching the water go in (I diluted the salt in 20 litres of water) made me nervous, as you could clearly see the shimmer of the denser water coming out the siphon hose. It looked like I was adding syrup!

The fish seem quite content though!

Stephen.

 

[Dubby]

Bascially the specific gravity of a sample is a function of its salinity and its temperature.

thats a basic description
is there an even more basic description, one that I can understand?
I doubt it.

[snapback]702075[/snapback]​

Paul, How about this ?

The specific gravity is directly proportional to the salinity and inversely proportional to the temperature