Saltwater mixing question

[mmorrison55]

I picked up a box (200 gallon) of instant ocean purple that has 4 bags. So l assume that each bag would be good for mixing up 50 gallons. My mixing containers are 65 gallons, but I filled it with Rodi to a bit over 50 gallons. In hindsight, I probably should have drained it to be as close to the 50 mark as possible, but I left it around ~52.

Anyways… since adding the bag and mixing for several hours using a recycling circulation (no pump inside the tank). Left it to sit overnight, then ran the pump again for a few hours this morning, I’m reading 27.0 ppt on my Hannah checker HI98319U. 27 ppt=1.0203 specific gravity.

Finally to my question… do you guys have a formula or process to know how much salt in volume or weight to add if you need to increase the salinity in “x” amount of water? For reference, the tank on the right is my saltwater holding tank and it shows the mixing method flow. Basically just recycling in from the top and out the bottom in a closed loop once the needed valves are closed.

 

[Kingsley_Reef]

I’m roughly 3.3 lbs of salt per 10gals of Rodi water to get 1.026 however this sometimes is not 100% bag per bag bucket per bucket but it’s close I mix for 24 hours heated to roughly 80 check add salt or Rodi as needed mix for another 3-4 hours before use

The BRS salt mix calculator is also very helpful https://www.bulkreefsupply.com/reef-calculator/salt-mix-calculator

 

[fishyjoes]

The number of gallons on the box (200) is assuming a relatively low salinity (it's on the box somewhere if you read all of that).
I use the "direct salt addition" calculator from hamzasreef.com to get close to my desired salinity, then measure and adjust from there (because, like you, I don't know exactly how much water I started with).

https://www.hamzasreef.com/Contents/Calculators/DirectSaltCalculator.php

 

[mmorrison55]

Thanks for both links. Both provided a very different result…


For water volume 52 us gallons, current salinity of 27.0 with desired salinity of 33…

The BRS calculator using the instant ocean drop-down, told me I need to add 2.95 lbs of salt.

The hamzareef direct salt calculator is reporting I need to add 3.24 lbs of salt.

I picked 33 ppt because my mixing tank is not heated and the current ambient temp is 72. I suspect if I heat the water up to 77, my salinity will go up a bit, so wanted to leave room for adjusting. Plus my tank is currently at 35.3 so I’d like to bring it down a bit when I do a water change.

Anyway, I’ve gone with the BRS suggestion. I will mix and test again later tonight and see if it’s close or if I should have gone with the hamzareef calculator

Thank you both for your feedback

 

[rtparty]

The 50 gallon bags makes 50 gallons at like 1.019 or something around that. The 200g box makes 160ish gallons at 1.026