Water temp and salinty

cgib831 · 10/04/2007, 11:33 AM

I was searching for this while doing a water change the other day and found only highly scientific answers --- how does temp effect salinty? I mix 20g of deio water at a time for water changes, and usually heat the water to tank temp before i add salt to make sure specific gravity is correct. But it is a pain and takes a long time. So if my tank is 78 degrees and 1.024, how should i mix my water if it is 70 degrees. higher or lower specific gravity?

OliverM3 · 10/04/2007, 12:11 PM

You could just pick up a refractometer. The couple drops of water only take 30 sec to reach the temperature of the refractometer.
So you would be able to get an accurate reading at any water temp.
But you really should bring the water temp close to your tank temp before doing a water change to reduce stress.

Wryknow · 10/04/2007, 12:14 PM

Temperature will make a minor effect on specific gravity (warmer water is somewhat lighter until you get down to freezing anyway.). A lot of refractomoeters will autocompensate for it, some do not. I wouldn't really worry about it myself. At 10 degrees farenheit the difference in density is probably less than the resolution of your measuring tool. If you wanted to shoot for 1.025 for the slightly colder water it probably wouldn't hurt anything. (You could also just throw a heater into your top-off water container until it matches the tank temperature, which is a good idea anyway just to reduce stress from the water change.)

cgib831 · 10/04/2007, 02:56 PM

yeah, ive been doing the heater thing for a while. still takes a long time to heat 20 gls up even with a 400 watt heater. I dont think that drop is gonna hurt anything. not worried about that, just inconveinant (?)

Bebo77 · 10/04/2007, 03:05 PM

i always put a heater in with the RODI water then i mix the salt.. make sure you measure how much you are adding so that you know exactly how much to add for future water changes...

10/04/2007, 11:33 AM	#1
cgib831 Registered Member Join Date: Jan 2007 Location: Westchester, NY Posts: 143	Water temp and salinty I was searching for this while doing a water change the other day and found only highly scientific answers --- how does temp effect salinty? I mix 20g of deio water at a time for water changes, and usually heat the water to tank temp before i add salt to make sure specific gravity is correct. But it is a pain and takes a long time. So if my tank is 78 degrees and 1.024, how should i mix my water if it is 70 degrees. higher or lower specific gravity? __________________ I keep trying the same thing over and over, but it never works. Current Tank Info: 29g FOWLR, coming down soon. Recently purchased a 90g drilled. DIY stand and canopy.

10/04/2007, 12:14 PM	#3
Wryknow Registered Member Join Date: Jun 2005 Location: Austin, Texas Posts: 1,203	Temperature will make a minor effect on specific gravity (warmer water is somewhat lighter until you get down to freezing anyway.). A lot of refractomoeters will autocompensate for it, some do not. I wouldn't really worry about it myself. At 10 degrees farenheit the difference in density is probably less than the resolution of your measuring tool. If you wanted to shoot for 1.025 for the slightly colder water it probably wouldn't hurt anything. (You could also just throw a heater into your top-off water container until it matches the tank temperature, which is a good idea anyway just to reduce stress from the water change.) __________________ You cannot use reason to change the opinion of a person that did not use reason to form their opinion in the first place. Current Tank Info: 65 G RR, w/ 50 G sump/refugium, DIY LED lighting, AquaMaxx CO-1 skimmer, Tunze 1073.050 return

10/04/2007, 02:56 PM	#4
cgib831 Registered Member Join Date: Jan 2007 Location: Westchester, NY Posts: 143	yeah, ive been doing the heater thing for a while. still takes a long time to heat 20 gls up even with a 400 watt heater. I dont think that drop is gonna hurt anything. not worried about that, just inconveinant (?) __________________ I keep trying the same thing over and over, but it never works. Current Tank Info: 29g FOWLR, coming down soon. Recently purchased a 90g drilled. DIY stand and canopy.

10/04/2007, 03:05 PM	#5
Bebo77 Premium Nonpaying Member Join Date: Jul 2005 Location: Lost Posts: 14,377	i always put a heater in with the RODI water then i mix the salt.. make sure you measure how much you are adding so that you know exactly how much to add for future water changes... __________________ Gabriel Current Tank Info: 300 Gal Envision Tank(98Lx30Wx26T) 120 Gal SoCalCreations Sump, Deltec TC2560, 2 LumenarcsMini 1 Reg on a light mover W Radiums 250& 400, Gallaxy ballasts, Red Dragon 10m3 return W/ 2 WavySeas, 2 6155 Tunze streams

10/04/2007, 12:11 PM	#2
OliverM3 Registered Member Join Date: Aug 2007 Location: PA Posts: 616	You could just pick up a refractometer. The couple drops of water only take 30 sec to reach the temperature of the refractometer. So you would be able to get an accurate reading at any water temp. But you really should bring the water temp close to your tank temp before doing a water change to reduce stress.