Temperature measuring salinity or S.G.

DozerDozer · 11/30/2013, 08:14 PM

I've looked but haven't found an answer I understand.
My RODI is outside and gets cold about 55 degrees F. When I am mixing salt with water my refractometer says 1.025. How much does temperature affect my reading?

bnumair · 11/30/2013, 09:50 PM

All saltmix in market recommend mixing at 77F. i strongly advise to do the same. throw in a spare heater bring up the temp and mix salt. colder water mixes less hotter water mixes more salt. Refractometer can be off reading the salinity unless its ATC (Auto temp control) but it all depends on the range of ATC. i have a few that range from 40F to 140F some may only go from 60-120F so there are variables and in order to eliminate all the variable its best to bring the water to 77-78F and mix salt wait 2 hrs or so then check for salinity.
Also check the specs on your refrac and see the range on ATC if its ATC.

example: DD-Refrac ATC 50-86F

DozerDozer · 11/30/2013, 10:04 PM

Just picked up the milwuakee digital. Not sure if I can add a heater outside. Can I heat the water to 77-80 and then mix and test? How far off can it be if I mix at 55-60? I usually mix then heat the water to temperature as needed. What happens if I don't wait ~2hrs after mixing?

bnumair · 11/30/2013, 10:11 PM

i would heat first then mix salt when at 78F then wait atleast till its mixes clear and no cloudiness is left. checking it before that will never be accurate. Also i am guessing at colder temps unless your refractometer is ATC and 55F is within its range there will be variance and it could be off by few points.

bnumair · 11/30/2013, 10:14 PM

if you have the milwuakee refrac MA887 model then ur safe as long as you let the water sample sit on the prism and let the temp on LCD show very close to ur storage water then u can consider the readout as good.
ATC range on that unit is 32-176F. btw thats what i have.

11/30/2013, 08:14 PM	#1
DozerDozer Registered Member Join Date: Aug 2012 Location: San Diego Posts: 79	Temperature measuring salinity or S.G. I've looked but haven't found an answer I understand. My RODI is outside and gets cold about 55 degrees F. When I am mixing salt with water my refractometer says 1.025. How much does temperature affect my reading?

11/30/2013, 09:50 PM	#2
bnumair Dr. Reef at ur service Join Date: May 2009 Location: Tulsa, Ok, USA Posts: 7,751 Blog Entries: 15	All saltmix in market recommend mixing at 77F. i strongly advise to do the same. throw in a spare heater bring up the temp and mix salt. colder water mixes less hotter water mixes more salt. Refractometer can be off reading the salinity unless its ATC (Auto temp control) but it all depends on the range of ATC. i have a few that range from 40F to 140F some may only go from 60-120F so there are variables and in order to eliminate all the variable its best to bring the water to 77-78F and mix salt wait 2 hrs or so then check for salinity. Also check the specs on your refrac and see the range on ATC if its ATC. example: DD-Refrac ATC 50-86F __________________ Water Quality: NO3 0,Phos 0,Cal 440,Alk 7.5,Mag 1300 "Reef Fast, You Crash, Reef Slow, You Pass" Mike's Reef 3:16 Current Tank Info: 350g DT,95g sump, 50g Frag tank, 4800gph return 4x Sea swirls. 6x AI Vega Color. 200# Pukani rock, dual recirculating skimmer, Biopellet, GFO Carbon rx's, Cal rx. Closed loop. 1.5hp chiller, genesis renew. Apex & RKE Last edited by bnumair; 11/30/2013 at 10:02 PM.

11/30/2013, 10:11 PM	#4
bnumair Dr. Reef at ur service Join Date: May 2009 Location: Tulsa, Ok, USA Posts: 7,751 Blog Entries: 15	i would heat first then mix salt when at 78F then wait atleast till its mixes clear and no cloudiness is left. checking it before that will never be accurate. Also i am guessing at colder temps unless your refractometer is ATC and 55F is within its range there will be variance and it could be off by few points. __________________ Water Quality: NO3 0,Phos 0,Cal 440,Alk 7.5,Mag 1300 "Reef Fast, You Crash, Reef Slow, You Pass" Mike's Reef 3:16 Current Tank Info: 350g DT,95g sump, 50g Frag tank, 4800gph return 4x Sea swirls. 6x AI Vega Color. 200# Pukani rock, dual recirculating skimmer, Biopellet, GFO Carbon rx's, Cal rx. Closed loop. 1.5hp chiller, genesis renew. Apex & RKE

11/30/2013, 10:14 PM	#5
bnumair Dr. Reef at ur service Join Date: May 2009 Location: Tulsa, Ok, USA Posts: 7,751 Blog Entries: 15	if you have the milwuakee refrac MA887 model then ur safe as long as you let the water sample sit on the prism and let the temp on LCD show very close to ur storage water then u can consider the readout as good. ATC range on that unit is 32-176F. btw thats what i have. __________________ Water Quality: NO3 0,Phos 0,Cal 440,Alk 7.5,Mag 1300 "Reef Fast, You Crash, Reef Slow, You Pass" Mike's Reef 3:16 Current Tank Info: 350g DT,95g sump, 50g Frag tank, 4800gph return 4x Sea swirls. 6x AI Vega Color. 200# Pukani rock, dual recirculating skimmer, Biopellet, GFO Carbon rx's, Cal rx. Closed loop. 1.5hp chiller, genesis renew. Apex & RKE

11/30/2013, 10:04 PM	#3
DozerDozer Registered Member Join Date: Aug 2012 Location: San Diego Posts: 79	Just picked up the milwuakee digital. Not sure if I can add a heater outside. Can I heat the water to 77-80 and then mix and test? How far off can it be if I mix at 55-60? I usually mix then heat the water to temperature as needed. What happens if I don't wait ~2hrs after mixing?