Mixing IO Reef Cyrstals?

Sacohen · Jan 17, 2015

I just got a box of IO Reef Crystals and it recommends a 1/2 cup per gallon or 1.4lbs per 5 gallons for a specific gravity of 1.021.

I want 1.025 for my SW what would someone recommend for 5 gallons or per gallon?

I'm actually going to be doing 20 gallons at a time typically, but this will help get me started.

heathd.hd · Jan 17, 2015

I'm doing the same search.

Baldguy · Jan 17, 2015

Assuming you have a refractometer I'd add the 2 1/2 cups and then keep track of how much more you need to add to get to 1.025. That's for 5g. I wouldn't want to do it by weight.

JimWelsh · Jan 17, 2015

Taking the package instructions at face value, that's 0.5 cups / gal or 0.28 lbs / gal. To get your target SG, you need 25/21 times the amount recommended on the package, which is 0.595 cups / gal or 0.333 lbs / gal., which is 11.9 cups or 6.66 lbs for 20 gallons.

I find it most efficient to add just a bit too much salt, and then let it dissolve and aerate until clear. I then measure the SG with my refractometer, and add RO/DI as necessary to bring the salinity down to where I want it.

heathd.hd · Jan 17, 2015

JimWelsh said:
Taking the package instructions at face value, that's 0.5 cups / gal or 0.28 lbs / gal. To get your target SG, you need 25/21 times the amount recommended on the package, which is 0.595 cups / gal or 0.333 lbs / gal., which is 11.9 cups or 6.66 lbs for 20 gallons.

I find it most efficient to add just a bit too much salt, and then let it dissolve and aerate until clear. I then measure the SG with my refractometer, and add RO/DI as necessary to bring the salinity down to where I want it.

Looks great thanks for the work lol. 3 cups per 5g than tinker.

saltyhog · Jan 17, 2015

I use 15 cups to make 25 gallons which would translate to 3 cups/5 gallon or 0.6 cups/gallon

Sacohen · Jan 17, 2015

Thanks everyone. 3 cups pr gallon come out to 12 cups for 20 gallons which is very close to the 11.9 cups that JimWelsh calculated.
I think I'll start with that and see how it turns out,

NanaReefer · Jan 17, 2015

I use 2 3/4 cups per 5 1/2g water (salt added to bucket before water) and get 1.026sg 35ppm salinity.

JimWelsh · Jan 17, 2015

NanaReefer said:
(salt added to bucket before water)

Better to add salt to water, than the other way around. Adding water to salt might cause some undesirable precipitation.

NanaReefer · Jan 17, 2015

JimWelsh said:
Better to add salt to water, than the other way around. Adding water to salt might cause some undesirable precipitation.

Been doing it this way for 6yrs. It never has caused precipitation. Go figure

JimWelsh · Jan 17, 2015

Sorry, just regurgitating what I've been told over and over again. It may very well depend on how many gallons are being mixed up at once, the rate at which the water is added, the temperature of the water, etc. Or it could just be pure BS I'm guilty of repeating. I believe that as a general rule, it is preferable to add a solute to a solvent than the other way around. Maybe Randy has an opinion.

EDIT: I found the following quote from this link: The â€œHow Toâ€ Guide to Reef Aquarium Chemistry for Beginners Part 1: The Salt Water Itself by Randy Holmes-Farley - Reefkeeping.com

"Adding the salt before the water can be okay, but causes an unusually high salinity for the period when you are adding water, which can result in the formation of certain precipitates that may be hard to redissolve."

NanaReefer · Jan 18, 2015

Now I'm going to have to test my method to Randy's. See if I get the same SG & salinity readings as apposed to my normal way of mixing. I've never noticed a difference

Randy Holmes-Farley · Jan 18, 2015

If you do it fast, it likely won't matter, but if it takes too long to add the water and mix it, then you might get some calcium carbonate precipitate. The thing to look for being different is alkalinity, which would change the most.