question

[boxfishpooalot]

I got a salinity monitor. I got a refractometer. And a hydrometer.

The hydrometer and refractometer read the same 1.026 sg. The pinpoint monitor reads 1.018!

So im asking how much salt does it take in cups(actual measures) apporximately to make a sg of 1.026 in an instant ocean 5 gallon bucket? i get about 1 1/2 level cups approx for 1.026sg. What do you get?

Hopefully this will show any problems of wich reads true.

Thanks, Box :)

[Hop]

I run about 2.5 scoops per 5 gallon bucket. I even measured and marked the side of one of the buckets to ensure it was five gallons. Maybe the altitute effects it here though;)

[boxfishpooalot]

what device do you use? Refract?

[TOURKID]

me too. 2.5 cups in 1 5 gal bucket

[Hop]

Yup... Refractometer. I know it may be off a tad, but the difference between your 1.5 cup and my 2.5 is pretty crazy:) Maybe I'm high and your low. I don't know though. I'm guessing your monitor is probably more accurate at this point.

[boxfishpooalot]

How high is the water level in the 5 gallon before you guys add salt?

[Misled]

I use 2 cups per 5 gal bucket, but the bucket is only filled with a little over 4 gal of RO/DI. Usethe old floating hydrometer. Gives me temp at the same time.

[Hop]

<a href=showthread.php?s=&postid=8899369#post8899369 target=_blank>Originally posted</a> by boxfishpooalot
How high is the water level in the 5 gallon before you guys add salt?

I used a 1 gallon milk jug a few years ago and added one gallon at a time, marking each gallon with a marker. I would say the 5 gallon mark is about 2.5-3" from the top. But I have not done this in over a year... Now I add 25 scoops into my 44 gallon brute and then adjust acordingly:)

[Hop]

Ooops sorry. Meant 20 scoops and adjust accordingly. My internal calculator is broke:)

[reeformadness]

I think a refractometer is probably most dependable. It must be calibrated though. Test it with freshwater and make sure it reads zero. If not turn the screw under the rubber thingy until it does.

[Hop]

<a href=showthread.php?s=&postid=8899752#post8899752 target=_blank>Originally posted</a> by reeformadness
I think a refractometer is probably most dependable. It must be calibrated though. Test it with freshwater and make sure it reads zero. If not turn the screw under the rubber thingy until it does.

I believe this is what he is referring to. A recent thread presents evidence that supports the refractometers can be off quite a bit and zeroing them with RO water is not sufficient. One of the good scientists here at RC posted a calibration solution to test your refractometer, but I'm ashamed to say I have not tried it yet:)

[boxfishpooalot]

Yes im referring to that. But also that i have this pinpoint meter brand new showing somthing else.

Ok so it takes me 2.5 cups of io salt to reach a sg of 1.026 exact. The bucket has water thats 3" below the surface.

Anybody here have a pinpoint meter?

[Im14abeer]

The calibration solution for your monitor is cited in aforementioned thread/reefkeeping magazine arcticle last month, as an appropriate calibration solution for your refractometer. Also, on a run of the mill 5 gallon bucket, the bottom of the reinforcement for the handle is very close to 4 gallons. Two cups of salt to that, and voila 1.025 or thereabouts.