Salinity/Specific Gravity/Temperature

[kadaytar]

There was a topic subjected as 'What specific gravity' a few days ago. Something made me confused. What i know is specific gravity does not mean salinty we use it as a key to figure out the salinty in our tanks. Salinity is the total amount of dissolved solids (in grams) in 1000 grams (1 kg) of water, and is described as(ppt) parts per thousand. The salinty levels of tropical seas where our animals come from are between 34-37ppt but the common is 35. Red Sea is the highest with 38 ppt. Since we can not find it out of laboratory conditions we use SG and temperature. Because SG changes proportionally depending on salinty and temperature. water having a salinty of 35ppt at 24 degree celcius gives us the SG of 1.0240. When we increase the temp from 24 C to 26C at the same 35ppt salinty SG is going to be 1.0267.

My question is at this point. Are we trying to reach the correct salinty around 35ppt or SG around 1.024. It does not make any sense on me because we can get this SG at very different temperatures and salinty levels much less or more than the salinty of tropical seas . shortly we can get it at wrong salinty. I am not very sure but for me it must be used as a key. Am i missing something?

Kadir

[Chrismo]

Your target specific gravity will change depending on Tank temperature, I believe the 1.025 setting often talked about is correct at 78 degrees. But there are charts online telling you what the correct SG to use at different temps.

Chris

[pluff]

Does anyone keep there salt higher than 1.025? Reason i ask this,is that i was talking to 2 marine biology students the other day at the pet store.They are keeping there salt at 1.032 in there reef tanks at there house.Thats what they say the water test here in the Bay of Fundy.So thats what tthey think is the right salinty.The fish that i remeber them having in there tanks was a yellow tang and a pair of Clowns,plus your regular soft corals.

Just thought i would throw that out there. :cheers: