Salinity calculator

MarksReef · 12/15/2018, 05:42 PM

90 gallons with a SG of 1.032
I want to be at 1.026
If I take out 4 or 5 gallons twice a day and replace with RODI, how long would it take?
Good plan to get back no normal?

bertoni · 12/15/2018, 06:51 PM

If that's 90 g of actual water volume, you would need to remove about 16 gallons of water. Personally, I'd do about 2 g per day via autotopoff, if I had a slow (peristaltic) pump, maybe in two shots. I'm assuming there are corals in the system, or other invertebrates (osmoconformers).

bertoni · 12/15/2018, 06:53 PM

The math:

1.000 SG means no salt content, so
.026 / .032 = .8125
is the amount of salt to keep.

So the amount of salt water to keep is:
.8125 * 90 = 73.125

MarksReef · 12/15/2018, 08:02 PM

Thanks you Bertoni

His did you get the = .8125 ?
Yes, about 90 G if water
Full reef.
I am using a litermeter for top off so I could take 3 gallons out every morning and have the litermeter replace in 24 hrs.
PS I don’t recommend the IceCap salinity tester.

bertoni · 12/15/2018, 08:44 PM

Oops, typos fixed. Sigh! The tanks current SG is 1.032. The target is 1.026. 1.000 actually corresponds to zero salt, so you want to dilute down to .026/.032 of what is in the system, which is .8125.

lapin · 02/09/2019, 09:11 PM

Quote:

Originally Posted by bertoni

Oops, typos fixed. Sigh! The tanks current SG is 1.032. The target is 1.026. 1.000 actually corresponds to zero salt, so you want to dilute down to .026/.032 of what is in the system, which is .8125.

Along these lines since im not a math wiz like you
If I have 100 gallons at 1.026 and I want to drop it to 1.023 how many gallons of saltwater do i replace with freshwater?

bertoni · 02/09/2019, 10:41 PM

I get about 11:
.026(100 - x) = .023 * 100
2.6 - .026x = 2.3
.026x = 0.3

I might try half that and see how it goes. I am assuming it's 100g of actual water volume in the system.

lapin · 02/11/2019, 08:44 PM

Quote:

Originally Posted by bertoni

I get about 11:
.026(100 - x) = .023 * 100
2.6 - .026x = 2.3
.026x = 0.3

I might try half that and see how it goes. I am assuming it's 100g of actual water volume in the system.

Thanks

bertoni · 02/11/2019, 10:20 PM

You're welcome. Please let me know how accurate my math was.

12/15/2018, 05:42 PM	#1
MarksReef Registered Member Join Date: Feb 2002 Location: Rush, N.Y. Posts: 4,058	Salinity calculator 90 gallons with a SG of 1.032 I want to be at 1.026 If I take out 4 or 5 gallons twice a day and replace with RODI, how long would it take? Good plan to get back no normal? __________________ 93G Rimless Cube Current Tank Info: 93G Rimless Cube

12/15/2018, 06:51 PM	#2
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	If that's 90 g of actual water volume, you would need to remove about 16 gallons of water. Personally, I'd do about 2 g per day via autotopoff, if I had a slow (peristaltic) pump, maybe in two shots. I'm assuming there are corals in the system, or other invertebrates (osmoconformers). __________________ Jonathan Bertoni

12/15/2018, 06:53 PM	#3
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	The math: 1.000 SG means no salt content, so .026 / .032 = .8125 is the amount of salt to keep. So the amount of salt water to keep is: .8125 * 90 = 73.125 __________________ Jonathan Bertoni Last edited by bertoni; 12/15/2018 at 08:43 PM. Reason: typos fixed

12/15/2018, 08:02 PM	#4
MarksReef Registered Member Join Date: Feb 2002 Location: Rush, N.Y. Posts: 4,058	Thanks you Bertoni His did you get the = .8125 ? Yes, about 90 G if water Full reef. I am using a litermeter for top off so I could take 3 gallons out every morning and have the litermeter replace in 24 hrs. PS I don’t recommend the IceCap salinity tester. __________________ 93G Rimless Cube Current Tank Info: 93G Rimless Cube

12/15/2018, 08:44 PM	#5
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	Oops, typos fixed. Sigh! The tanks current SG is 1.032. The target is 1.026. 1.000 actually corresponds to zero salt, so you want to dilute down to .026/.032 of what is in the system, which is .8125. __________________ Jonathan Bertoni

02/09/2019, 10:41 PM	#7
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	I get about 11: .026(100 - x) = .023 * 100 2.6 - .026x = 2.3 .026x = 0.3 I might try half that and see how it goes. I am assuming it's 100g of actual water volume in the system. __________________ Jonathan Bertoni

02/11/2019, 10:20 PM	#9
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	You're welcome. Please let me know how accurate my math was. __________________ Jonathan Bertoni