Salt to SG Table

[Roan Art]

I'm assuming rrkss will respond to this

Does anyone have an Salt to SG table made up? I don't wanna reinvent the wheel and I just don't have time to do the gallon/salt/refractometer dance atm.

Just to 1.005, please.

Thanks
Roan

 

[sumthin fishy]

Roan- are you asking for a table to show how much salt is needed (as in cups, tsp. what have you) to get a specific SG? I have no clue about this subject, but I recall RTR telling someone not to go by a specific measuring tool, other than the refractometer, since measuring devices can be slightly inaccurate. It may be there is a general guide, but you would still want to measure to be sure. (kind of like how much ammonia to use in a fishless cycle) But then I could be way off on this one

 

[Roan Art]

I wanna table showing x teaspoons = SG

It's just for a guideline as I always double check with my refractometer.

The thing is, just because I have 75g tanks, does not mean there are 75 gallons of water in each one. One has about 64g and the other has about 54g. Lots of substrate

Roan

 

[rrkss]

I usually add salt slowly until I get my desired SP. I use 1.005 to kill ich which is probably a bit to the high side. It takes me 7 teaspoons of rock salt in my 3.3 gallon container to reach that point. That is about 2 teaspoons per gallon. I am not sure what tablesalt would do. Maybe the next time I make some RO/DI water, I'll spare a gallon and add salt to it and see what the effects are.

 

[OrionGirl]

sumthin_fishy is right. There are a number of problems with trying to use volumes, including the type of salt (marine mix vrs table salt vrs sea salt, where the amount of NaCl varies with each) and the humidity.Specific gravity is also complicating the matter, since SG changes with temperature. You can use a general guideline, but it won't be accurate enough to be useful, particularly at lower levels of salinity.

Here's an interesting link: http://www.algone.com/salinity.htm

Here's a formula that will work better: Multiply % difference x # of gallons of water X 8.344 = pounds of salt needed.

 

[patoloco]

Refractometer vs. hydrometer. Need opinions.

 

[OrionGirl]

Refractometer. Hydrometers are useful, but imprecise. Hydrometers can be used once calibrated, if properly cleaned and stored, but it's still best to verify with a refractometer regularly.

 

[Roan Art]

Refractometer. Hydrometers are useful, but imprecise. Hydrometers can be used once calibrated, if properly cleaned and stored, but it's still best to verify with a refractometer regularly.

I re-calibrate my refractometer at least once a month. I don't use it a lot, so I'd have no clue if it was "off" or not.

Roan

 

[Roan Art]

sumthin_fishy is right. There are a number of problems with trying to use volumes, including the type of salt (marine mix vrs table salt vrs sea salt, where the amount of NaCl varies with each) and the humidity.Specific gravity is also complicating the matter, since SG changes with temperature. You can use a general guideline, but it won't be accurate enough to be useful, particularly at lower levels of salinity.

Depends on what you'd consider "useful" I guess I should have specified Morton's table salt, which is what I use.

Here's an interesting link: http://www.algone.com/salinity.htm

Hrm, you know, I didn't think about that. Weight I mean. So any tank that is high in TDS is going to read higher than it actually is, which will vary from tank to tank in my house.

I'm wondering -- if I calibrate the refractometer with the water from the tank that I intend to add salt to, then the readings I take thereafter will be more "specific" to how much salt I put in, correct?

Here's a formula that will work better: Multiply % difference x # of gallons of water X 8.344 = pounds of salt needed.

I'll try that, thanks.

Roan

 

[OrionGirl]

Sort of-if you'd be better off calibrating against RO, then test the water without salt and then with salt, and make a comparison between those 2 values, I think.