Heater Packed Up For My Salt Mix Container!

[woody88]

hi, as the topic title says my heater died today so is it ok to mix salt in COLD RO.

I know how much salt to add to get required sg but when up to temp. I have added same amount again in cold RO but SG only reads 1.020. Can I assume when up to tank temp it will reach 1.025 sg like it normally is when I do wc?

Cheers Stewart.

 

[jameshughes1989]

I dont know to be honest. What refractometer are you using? The deltec one I use states that the temp does not effect the reading. I would also be very wary about adding cooler water into a marine tank through fear of shock.

HTH

 

[seffieuk]

SG is affected by temp

Why not just heat it up in a saucepan and add to cold water that's what I would do if I didnt have a spare which of course I do

Seffie x

 

[simonas]

SG is affected by temp

your joking!!!! I mix mine in an unheated tub and then add unheated!!

 

[StandbySetting]

Changing the temperature of a solution will change it's density thus changing its refractive index, so you wont get an accurate reading from a refractometer.

 

[jameshughes1989]

Changing the temperature of a solution will change it's density thus changing its refractive index, so you wont get an accurate reading from a refractometer.

Ah yes, I believe that is true. Surely then, from the OP original question, if he added the water to the tank cold, once it heated up it would be at the correct level? Is this correct?

 

[woody88]

So basically what your all saying is 'BUY A HEATER YOU CHEAP SKATE' lol

If it is possible to do then I would prefer to do it this way as it means i aint got to pre mix the night before a wc to allow it to heat up to temp.

Changing the temperature of a solution will change it's density thus changing its refractive index, so you wont get an accurate reading from a refractometer.

Ah yes, I believe that is true. Surely then, from the OP original question, if he added the water to the tank cold, once it heated up it would be at the correct level? Is this correct?

Thats the question i was gonna type again!........Anyone got an answer to this please.

 

[seffieuk]

So basically what your all saying is 'BUY A HEATER YOU CHEAP SKATE' lol

yep!

Have a little look........

http/www.aquatronica.com/pdf_download/eng/sale_in_acquario_marino_EN.pdf

Seffie x

 

[StandbySetting]

No because if you make the solution up with the water at room temperature, and then test it's refractive index which is then converted to specific gravity with the indicator you look at, it gives you a value for specific gravity at room temperature, not at the desired temperature of 25-26oC, if you make a solution at 20oC to a specific gravity of 1.024 and then heat it and test it again you will get a lower specific gravity, due to the relationship between temperature and density, to get an accurate reading of salt content the water you make the salt water up in must have a temperature of 25oC, because this is generally (refer to your instructions) what the refractometer is calibrated to.

 

[woody88]

So basically what your all saying is 'BUY A HEATER YOU CHEAP SKATE' lol

yep!

Have a little look........

http/www.aquatronica.com/pdf_download/eng/sale_in_acquario_marino_EN.pdf

Seffie x

Just read through that link [well, tried to!] and after reading it, my conclusion is this!..........you need a #138## PHD to understand it! lol

Still, will save the link anyway and paste it as my desktop background so when people see windows on my laptop they'll think i'm clever g1t! lol

Thanks Seffie

 

[seffieuk]

Still, will save the link anyway and paste it as my desktop background so when people see windows on my laptop they'll think i'm clever g1t! lol

thought it was just me...

Seffie x

 

[woody88]

Still, will save the link anyway and paste it as my desktop background so when people see windows on my laptop they'll think i'm clever g1t! lol

thought it was just me...

Seffie x

I find it hard to believe that the 'Queen of Marine' Does'nt understand it! lol

 

[jameshughes1989]

No because if you make the solution up with the water at room temperature, and then test it's refractive index which is then converted to specific gravity with the indicator you look at, it gives you a value for specific gravity at room temperature, not at the desired temperature of 25-26oC, if you make a solution at 20oC to a specific gravity of 1.024 and then heat it and test it again you will get a lower specific gravity, due to the relationship between temperature and density, to get an accurate reading of salt content the water you make the salt water up in must have a temperature of 25oC, because this is generally (refer to your instructions) what the refractometer is calibrated to.

I understand that. Surely though, for example if you added x amount of salt to x amount of water and at 25oC it read 1.026. Then if you added the same x amount of salt to the same x amount of water that was cold, say 20oC it would obviously not read the same but once this was heated to 25oC it would then be 1.026? Unless I am completely not getting this.

Still, will save the link anyway and paste it as my desktop background so when people see windows on my laptop they'll think i'm clever g1t! lol

thought it was just me...

Seffie x

I find it hard to believe that the 'Queen of Marine' Does'nt understand it! lol

That was confusing for me too

 

[StandbySetting]

I understand that. Surely though, for example if you added x amount of salt to x amount of water and at 25oC it read 1.026. Then if you added the same x amount of salt to the same x amount of water that was cold, say 20oC it would obviously not read the same but once this was heated to 25oC it would then be 1.026? Unless I am completely not getting this.

Yes that is true, if you're accurate with preparations though, temperature doesn't need to be compensated for so it should pose no problems, sea water has a NaCl content of 33 parts per thousand so adding 0.033 Kg of NaCL salt to 0.967 Kg of RO water at any temperature will give you 33 parts per thousand or a specific gravity of 1.02485, which is rounded to 1.025.

 

[jameshughes1989]

Okay cool, you seem to know your shizzle