Cups of Salt = Salinity

merredeth

Active Member
I'm curious to know what brand of salt you use and to make your water up how much of a cup of salt, per gallon each person is using to arrive at their desired SG and salinity.
The reason I am asking this is I have had to vary the amounts of salt each time I make it to maintain a consistent 1.025 the last few times I made up 50 gallon water changes.
Thanks,
Denise M.
 

chub

Member
I use IO I put 25 cups for 55 gal of water and MY salinty was almost 1.60 I took out 5 gals and added 5g of R/O water ( THERES NOTHING IN THE TANK) will test again in 24hrs
 

rs1831

Active Member
I use reef crystals and I use half a cup per gallon of water. I check the salinity when I first make it up and then I use a power head and a heater and I let it circulate for at least 24 hours and then I check it again. Its always right around 1.023 and 1.025.
 

merredeth

Active Member
Originally Posted by chub
I use IO I put 25 cups for 55 gal of water and MY salinty was almost 1.60 I took out 5 gals and added 5g of R/O water ( THERES NOTHING IN THE TANK) will test again in 24hrs
You are going to need more RO water I can tell you that much already.
Whew! I'm glad to know nothing is in the tank yet.
Denise M.
 

djm

Member
I know mine exactly. I use Reef Crystals and mix it 5 gallons at a time using RO/DI water. It takes 2 3/4 cups (22 ounces) of salt to bring 5 gallons of water to 1.024.
 

merredeth

Active Member
Originally Posted by rs1831
I use reef crystals and I use half a cup per gallon of water. I check the salinity when I first make it up and then I use a power head and a heater and I let it circulate for at least 24 hours and then I check it again. Its always right around 1.023 and 1.025.
That is about where I am at with salt as well. However, going from 1.023 to 1.025 seems to require a bit more.
Maybe it has something to do with how the salt sits in the measuring cup, I'm not sure though. That's why I thought I would ask everyone.
Denise M.
 

merredeth

Active Member
RS and DJM - Did you read eachother's post?
See what I mean about the difference in measurements?
Denise M.
 

dragonzim

Active Member
I use IO also, but weigh the salt instead of measuring it out in cups. 1 1/2 lbs makes 5 gallons of water at 1.025
 

rs1831

Active Member
What are people using to measure there salinity. I use a refractometer now but in the past I used a hydrometer and wasn't nearly as accurate as my refractometer.
 

opus18

Member
Originally Posted by rs1831
What are people using to measure there salinity. I use a refractometer now but in the past I used a hydrometer and wasn't nearly as accurate as my refractometer.
Bought and tossed the hydrometer... Bought a great refractometer (same one my LFS uses) and love it...
 

merredeth

Active Member
Originally Posted by rs1831
What are people using to measure there salinity. I use a refractometer now but in the past I used a hydrometer and wasn't nearly as accurate as my refractometer.
I use the refract as well - yet I'm seeing a little swing and can't help but wonder what is up with the changes?
Denise M.
 

merredeth

Active Member
Originally Posted by DragonZim
I use IO also, but weigh the salt instead of measuring it out in cups. 1 1/2 lbs makes 5 gallons of water at 1.025
Hmmm.... maybe you are on to something here.
Denise M.
 

djm

Member
I use a Coralife Deep Six hydrometer. It is consistent to itself every time. Even if 1.024 on its scale may be off by one or two ten-thousanths in reality, it is still always consistent. I have tested mine with the same mix at 3 different temperatures in a 10 degree range.
Pick a number on ANY unit that has worked for you, and stick with it.
That said, a refractometer definitely will give you a more accurate ACTUAL NUMBER, but really isn't much more consistent than an hydrometer.
 

hatessushi

Active Member
I use a digital probe (Pinpoint Salinity monitor) and am able to hit it every time. It is more accurate when compared with a refract and Hydro.
 

moneyman

Member
Is it SG 1.06 or 1.60? Did you take the reading at normal tank temperature around 70-80 deg?
SG 1.60 is very VERY salty.
If it is SG 1.06, you'll need about 50% water change. Also, keep in mind that your 55 gallon does not hold 55 gallon of water. You are not filling to the rim and you prob have sand and/or rock to displace the water.
Originally Posted by chub
Do you think another 10g of R/O water would drop it down to a safe level
 
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