The bag of salt mix says 1/2 cup per gallon but.....

[SaltyMist]

I have a bag of salt mix that says to mix it at half cup per gallon of water. So since one of my 5 gallon containers was empty, I filled it with 5 gallons of distilled water, and added the 2.5 cups of salt mix.

Put a small powerhead inside the container along with a heater and let it mix away.

Now I ran a SG test on it and it's showing off the scale, on a swingarm hydrometer (yes, I do realize they are not exactly perfectly accurate, but it shouldnt be so off as to peg the scale at 1.30).

So what gives?

Is there a specific type of measuring cup that I should be using for measuring my salt or what? Im using simple kitchen measuring cups (used a 1 cup measure twice, then a half cup measure once), to make up my 2.5 cups of salt mix to mix with the 5 gallons (Im sure the gallons of water are correct since I used my aquarium mop bucket that has measurements on the inside up to 2 gallons, twice, and up to one gallon once, which measured on the container exactly in at 5 gallons).

Maybe there is some other type of measuring cup I need to get, I mean I know there is a difference between liquid measure and dry measure, so perhaps there is a specific measuring cup for salt mix?

Thanks, sorry for the long post.

 

[Mikef1]

Usually when I use this method it is very close. My hydrometer was off by .04 which is a lot. I checked it up against a refractrometer. Also how long did you let it mix?

 

[SaltyMist]

I let it mix for aproximately 18 hours. Along with quite a few manual "shakes" of the container, maybe 5 minutes of manuall shaking the container back and forth (what a workout that was )

 

[Mikef1]

Wow that is strange. Do you have a LFS that can check your salinity with a refractrometer?

 

[SaltyMist]

Believe it or not, the really local LFS says that refractometers are *too expensive* and he doesnt stock them, nor does he use them.

I guess I'll have to pop for one of those $49.00 refractometers that I've seen here or elsewhere.

 

[Mikef1]

Just make sure you get one with auotomatic Temperature compensation (ATC)

 

[Anonymous]

im pretty sure your salt to gallon mixture is right...i think your hydrometer is off..you know they calibrated within certain temps so they SG will change with the rise and fall of temp in your water according to your hydrometer... i agree with the refractometer...

HTH

 

[hdtran]

I use 2 cooking measuring cups to 4 gallons of water in a 5 gallon paint bucket. Works for me... (gets into the 1.021 range for me).

 

[SaltyMist]

Okay, I think LordNikon hit it on the head. While my home mixed saltwater was up to 78 to 80f, the store bought real ocean water was much colder, probably around 65 to 70f, and when mixing the two into the tank it brought down the temperature enough to throw off the reading.

Now that the temps up to 78 to 80f in the tank the hydrometer is reading it around 1.023 or 1.022 So all is well again.

 

[rwoolley]

You may want to heat that water up to temp before adding it to a tank with livestock.

 

[SaltyMist]

Thanks, yeah, Im gonna start doing that, by filling the bathtub with the right temp water, and putting a 2 gallon bucket with real ocean water in it, then wait till it hits the right temp before putting it in my tank.

I just didnt think to do it on the new tank.

 

[hdtran]

Saltymist,

Before I bought a spare heater (which is in my saltwater mixing container), what I would do was to nuke a cup or two of water & pour it into the saltwater bucket to get it up to temperature...

 

[saltnmyeye]

i use instant ocean salt. i mix it just like you did and i come up with a perfect 1.023 every time. i have a deep six hydrometer and it is only off .02 i had it check by my lfs. so i put a little more in until my hydrometer says 1.025 and i have 1.023. :wink: