Salt Mixing Time?

pulpfiction

Community Member
View Badges
Joined
Jan 26, 2021
Messages
76
Reaction score
28
Location
United States
When I mix salt, how long does it take for the salt to fully dissolve with a powerhead moving the water? When is it safe to add to a tank assuming the salinity and temperature is okay? If I add more salt to adjust salinity, is there a rule of thumb wait time before adding the water to the tank?
 
OP
P

pulpfiction

Community Member
View Badges
Joined
Jan 26, 2021
Messages
76
Reaction score
28
Location
United States
This is different for just about every brand of salt, but a lot of brands say their salt is safe for use after everything has fully dissolved. What salt do you use?
Instant Ocean. The container doesn't say how long to wait. It just says, "may be used immediately, we suggest aerating the water until it achieves oxygen/carbon dioxide equilibrium." It's a bit vague.
 
First Choice

BoxKing

Active Member
View Badges
Joined
Mar 31, 2021
Messages
114
Reaction score
92
Location
Philadelphia
Safest way to mix salt is to prepare it the night before a water change, and let it run for the 8-12 hours. Other than that, I’d say 2-4 hours, at or near temp when mixing with a pump should be sufficient as well for most salts offered.
I keep my temps around 70-75*, then raise to tank temp 78* when I’m ready to do my change.
 

PeterC99

Valuable Member
View Badges
Joined
Aug 28, 2020
Messages
1,384
Reaction score
3,166
Location
White Plains
Instant Ocean. The container doesn't say how long to wait. It just says, "may be used immediately, we suggest aerating the water until it achieves oxygen/carbon dioxide equilibrium." It's a bit vague.
Honestly, If these are the directions - then it’s time to get a new brand of salt mix!
 

Zer0

Active Member
View Badges
Joined
Jun 11, 2011
Messages
292
Reaction score
262
Location
NJ
Instant Ocean. The container doesn't say how long to wait. It just says, "may be used immediately, we suggest aerating the water until it achieves oxygen/carbon dioxide equilibrium." It's a bit vague.
I also use IO salt, it usually fully dissolves in under 30 minutes in my experience. Generally speaking, I mix a fresh bucket to 1.025 and then let it sit with a powerhead overnight. However for what it’s worth I have used a fresh batch about 45 minutes after mixing with no problems.
 
OP
P

pulpfiction

Community Member
View Badges
Joined
Jan 26, 2021
Messages
76
Reaction score
28
Location
United States
Does it depend on the amount of salt/water, too? I mix 5 gal
Honestly, If these are the directions - then it’s time to get a new brand of salt mix!
I was surprised to say the least.

Does it depend on the amount of salt/water, too? I mix 5 gallons at a time. I suppose I can't go wrong with mixing overnight?
 

Zer0

Active Member
View Badges
Joined
Jun 11, 2011
Messages
292
Reaction score
262
Location
NJ
I can’t remember off the top of my head, but on the bag/box it should say how much the salt:water ratio is. I think it’s 1/2 cup of salt per gallon for small quantities. Ideally though, you use the instructions on the box as a guideline and make sure you use your refractometer/hydrometer/whatever to confirm the salinity before use.
 
Orphek OR3 reef aquarium LED lighting
OP
P

pulpfiction

Community Member
View Badges
Joined
Jan 26, 2021
Messages
76
Reaction score
28
Location
United States
I can’t remember off the top of my head, but on the bag/box it should say how much the salt:water ratio is. I think it’s 1/2 cup of salt per gallon for small quantities. Ideally though, you use the instructions on the box as a guideline and make sure you use your refractometer/hydrometer/whatever to confirm the salinity before use.
Sorry I meant the mixing time. I follow the salt:water ratio that's on the container and adjust with a refractometer. I was also concerned about how long I should wait to mix so I know I'm getting a good specific gravity reading.
 

PeterC99

Valuable Member
View Badges
Joined
Aug 28, 2020
Messages
1,384
Reaction score
3,166
Location
White Plains
Does it depend on the amount of salt/water, too? I mix 5 gal

I was surprised to say the least.

Does it depend on the amount of salt/water, too? I mix 5 gallons at a time. I suppose I can't go wrong with mixing overnight?
Per Marine Depot

“Once the desired salinity level is reached you should let the water continue to mix and aerate for the amount of time recommended by the manufacturer. Some salt mixes are best used within 3-4 hours of mixing while others should mix for 12-24 hours before use.”
 

Dan_P

Valuable Member
View Badges
Joined
Sep 21, 2018
Messages
2,060
Reaction score
1,919
When I mix salt, how long does it take for the salt to fully dissolve with a powerhead moving the water? When is it safe to add to a tank assuming the salinity and temperature is okay? If I add more salt to adjust salinity, is there a rule of thumb wait time before adding the water to the tank?
There is no magic here. When the solid is gone, the salt is dissolved. Even if the specific gravity is the same, there are caveats.

Dissolution of salt might chill the water. The oxygen content might be different from water that is allowed to mix several hours, The same can be said about the carbon dioxide content and pH. Do these differences matter? If you are doing a 10% water change, none of these parameter differences are likely to matter. If you are doing a large water change, then you might want the temperature and pH to be closer to that of the system.
 
OP
P

pulpfiction

Community Member
View Badges
Joined
Jan 26, 2021
Messages
76
Reaction score
28
Location
United States
Per Marine Depot

“Once the desired salinity level is reached you should let the water continue to mix and aerate for the amount of time recommended by the manufacturer. Some salt mixes are best used within 3-4 hours of mixing while others should mix for 12-24 hours before use.”

There is no magic here. When the solid is gone, the salt is dissolved. Even if the specific gravity is the same, there are caveats.

Dissolution of salt might chill the water. The oxygen content might be different from water that is allowed to mix several hours, The same can be said about the carbon dioxide content and pH. Do these differences matter? If you are doing a 10% water change, none of these parameter differences are likely to matter. If you are doing a large water change, then you might want the temperature and pH to be closer to that of the system.
The replies help me understand. Thank you.
 

SchrutesReefs

Active Member
View Badges
Joined
Mar 25, 2021
Messages
217
Reaction score
269
Location
East Coast
Also, fwiw I also use IO reef crystals and the package does say 1/2 per gallon. I always need more than that to achieve 1.025 salinity. I also mix overnight, just a 5g wc for me each week.
 
Corals.com

rezaktp

Community Member
View Badges
Joined
Jan 17, 2013
Messages
32
Reaction score
18
Location
Northern IL.
I go 24 hours since I have a 100 Gal storage tank for my salt. I would think overnight is fine for a routine water change. In an emergency just look to see if it is visually dissolved probably in 2-4 hours.
 

gabrieltackitt

Well-Known Member
View Badges
Joined
Mar 23, 2020
Messages
548
Reaction score
1,044
Location
Tulsa, OK
I think from what I’ve seen/read. 12-24 hours for most salts is a good time to let pH, O2 and CO2 to come to full equilibrium. So I would probably say that, unless you are using a probiotic/biologically active salt.

Also I almost always add a little more salt than I think necessary, I’ve found that it is easier and faster to add RODI to lower the sg than trying to add a small scoop more of salt to bring it up.
 
OP
P

pulpfiction

Community Member
View Badges
Joined
Jan 26, 2021
Messages
76
Reaction score
28
Location
United States
I'm still trying to get the mixing process right...I did the recommended 1/2 cup for each gallon and let it sit over night with a heater and powerhead running. The salinity was below 1.20. I've been trying to adjust it all day and I'm at 4 1/2 cups in 4 gallons and the salinity is still showing low for that much salt at 1.21. I'm think the refractometer is calibrated and I'm double checking with a hydrometer. They're reading the same.
 
Last edited:
OP
P

pulpfiction

Community Member
View Badges
Joined
Jan 26, 2021
Messages
76
Reaction score
28
Location
United States
Salinity of 1.20? If that is correct, that is extremely high. You should be shooting for 1.0265. You need to add like a gallon or more of RO to drop that back down.
Oops. I meant 1.020 and 1.021. 1.20 would be crazy lol. I'm trying to shoot for 1.025 or 1.026. It feels like I'm adding a lot of salt yet its still low.
 
MotorCityCorals

What temperature do you think it too high for your reef tank?

  • 79

    Votes: 53 10.4%
  • 80

    Votes: 94 18.4%
  • 81

    Votes: 93 18.2%
  • 82

    Votes: 112 21.9%
  • 83

    Votes: 79 15.5%
  • 84+

    Votes: 64 12.5%
  • Other (please explain)

    Votes: 16 3.1%
Premium Algae Scrubbers from Turbo's Aquatics!
Top