Specific Gravity Question

[BriGuyRN]

I have a 60 gallon tank. I put in the salt last night and checked SG this morning, it was 1.030. I need to get it between 1.020-1.024. Any ideas how many gallons of saltwater i need to exchange out for freshwater?
Thanks!

 

[MondoBongo]

it's going to vary a bit based on the volume your rocks, sand, and equipment take up. whether or not you're running a sump, etc...

actual water volume can be quite different from the calculated volume of the tank, so my advice would be to get a 5 gallon bucket, drain out some of the water, and add a little fresh water, about a 1/2 to 1 gallon at a time, until you reach your desired level. waiting 30 - 60 minutes in between your adjustments. it will help if the tank is the correct temperature, and all your pumps and powerheads are running to move the water around as well.

to get a better estimation, there are some salinity calculators out there, like this one:

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

or

http://www.saltyzoo.com/SaltyCalcs/SalinityAdjust.php

 

[nuttyd]

First, established tank or new? Corals or Fish? I would do a gallon at a time until you get to level you want. Fish is lower, maybe 1.020. Corals higher, 1.024-1.026.

 

[BriGuyRN]

Thanks guys, I should have given more specifics!
60 gallon tank,
New. The only thing I have in it right now are crushed coral for the substrate. I have not bought the live rock yet, trying to get the SG calibrated before putting in Live Rock and starting the cycling process.
This will be a Fish Only tank.

 

[hkgar]

They all start as fish only, till you buy that first coral. You'll see something that really looks cool at the LFS and then..............

 

[BriGuyRN]

Well for NOW its fish only, this is my first saltwater aquarium

 

[Pickupman66]

How are you checking your Specific gravity? if with a swing arm Hydromeer they can be extremely inaccurate. best way is with a refractometer.

 

[fishgate]

Temperature is super critical. I would go with 78 degrees and 1.025 with a refractometer. I would remove 5 gallons (save it) and add 5 gallons of fresh water as a start. Then 1 gallon at a time until you reach the desired level.

 

[cloak]

Check this out.

http://www.advancedaquarist.com/2002/1/chemistry

HTH.

 

[tzylak]

. . . ."How are you checking your Specific gravity? if with a swing arm Hydromeer they can be extremely inaccurate. best way is with a refractometer. " . . . .

Although the above might be true, note that hydrometers are inexpensive and remarkably consistent, even though they might have a constant drift up or down on the scale. Still, that drift does not deviate.
Also, the refractometers need periodic calibration, and even that might be erroneous.

I vote 100% to use the first. I would not trust 100% the latter. If in doubt, get both.

 

[BriGuyRN]

What do you guys think about this Refractometer:

http://www.amazon.com/dp/B00XT2GFAU?psc=1#customerReviews