How many cups of salt to add

[Ando]

Hey quick questions.

 

How many cups of Instant Ocean Reef Crystals do you guys add for 5 gallons?

 

OR What do you add per gallon...

 

I know this is a dumb question, But I can seem to get 1.025 every time lol.

[marinebiologist]

1/2 cup for every gallon

[Scott Riemer]

You still need to test and adjust.

[Ando]

I will usually test it.. But I can't ever seem to get it at 1.025. lol Unless I add pure water to it.

[Kool-cat]

I usually add like 3 cups of Tropic Marin .

[m'akoyPINOY]

i do w/c with use the reef crystal bucket.7 cup and it's 1.026..

[Ando]

i do w/c with use the reef crystal bucket.7 cup and it's 1.026..

 

So u mean 2/3 Cup per gallon?

 

I would like to get the salinity at 1.026

[neanderthalman]

1/2 cup per gallon.

 

Careful though. I bought cheapo measuring cups just for this purpose...and they were not as labeled. The 1/2 cup was more like 7/8 cup.

[Ando]

Alright thanks!

[filefish949]

IIRC I use 8 pounds 9 oz for 30 gallons to get 35ppt

[lakshwadeep]

For Instant Ocean, you will need a little more than 0.5 cups per gallon. I think the manufacturer calculated 0.5 cups/gal for getting 1.023 instead of 1.025. In any case, it's easy to just put more than enough and then dilute with freshwater to the desired s.g. Don't forget to have proper temperature if you are using a hydrometer to test s.g.

[filefish949]

and don't forget to test for MG if you are using a refractometer

[PSYS]

I just got my pico up and running. I purchased Tropic Marin Pro Reef salt and I'm surprised there's no indication of how much salt to use anywhere on the box. It was a lot of trial and error until I got the right salinity. I would think they just could make a general blanketed statement like "Salinity = 1.024 if you use 1/2 cup @ 80 degrees." Or whatever.

 

Is the 1/2 cup per gallon a good general rule of thumb for most salt mixes???

[Scott Riemer]

Is the 1/2 cup per gallon a good general rule of thumb for most salt mixes???

That's what Oceanic recommends.

[SulfurAcid]

The best rule of thumb is probably to add the recommended amount, and always test using hydrometer, refractometer.

[Steel]

the temp of the water will cause the SG to vary.

[PSYS]

The best rule of thumb is probably to add the recommended amount, and always test using hydrometer, refractometer.

 

Yeah, that's what I mean... there's not even a "recommended" amount on this box of Tropic Marin Pro Reef. Not a big deal, but you'd think they'd provide that.

[filefish949]

the temp of the water will cause the SG to vary.

 

 

but not the salinity, that is why I like doing it by weight

[owned162]

and don't forget to test for MG if you are using a refractometer

 

Might be a stupid question, but why do you test MG if using a refractometer?

Cheers

[PSYS]

I e-mailed Tropic Marin last night and here is their reply:

 

"Hi Scott,

 

To get a specific gravity of 1.024 you need to add 4.5 cups of one of our salts each to 10 gallon of RO/DI water.

To get the average natural salinity of 35 ppt/psu equal to a specific gravity of 1.0264 you need to add 5 cups each ten gallon.

We can recommend to add 4.5 cups of salt to the RO/DI water, to check the specific gravity and to adjust the water to desired value.

 

 

I hope this helps.

 

 

All the best,

 

Lou Ekus

Director of US Operations

Tropic Marin USA

44 Center Street

Montague, MA. 01351

voice: 413-367-0101

fax: 413-367-0144

www.tropicmarin-usa.com

[filefish949]

Might be a stupid question, but why do you test MG if using a refractometer?

Cheers

 

 

because MG has a much higher refractive index than sodium chloride, and the salinity estimates made by a refractometer are dependant upon a known MG concentration

[owned162]

because MG has a much higher refractive index than sodium chloride, and the salinity estimates made by a refractometer are dependant upon a known MG concentration

 

Wow, after all the reading I've done over the last 2 years I've never heard this before... Thankyou

So what should the MG be at to have a salinity of 1.0264?

Cheers

[Ando]

alright well for 5 gallon I used 6 1/2 cups and my salt level was 1.026.

[Scott Riemer]

alright well for 5 gallon I used 6 1/2 cups and my salt level was 1.026.

Are you sure? That seems excessive. How are you testing?

[PSYS]

That really does seem excessive. I'm no expert and I know every salt mix will vary a little... but considering the guy at Tropic Marin advised: "To get the average natural salinity of 35 ppt/psu equal to a specific gravity of 1.0264, you need to add 5 cups each ten gallon."

 

You're well above that ratio even if we aren't talking about the exact same kind of salt mix. Could they realy vary by several cups of salt? I've no idea but it doesn't seem likely?