Mixing salt… reading 0 salinity

[Reefkeepers Archive]

To lump swing arm hydrometers into the same sentence as the Tropic Marin glass hydrometer does a serious disservice to both. The TM glass hydrometers are one of the best tools you can use to measure salinity. They are far better than the Milwaukee and its crazy margin of error. The Milwaukee can read 1.025 but actually be anywhere from 1.023-1.027 and be within spec.

I have a Milwaukee and use it regularly but I understand its limits and serious shortcomings.

Yes, in the that post I clarified that I have no experience with tropic Marin hydrometers, I assumed that they were talking about swing arm hydrometers, my bad, don't listen to my opinion on tropic Marin hydrometers, all I know is what works for me

 

[fishyjoes]

Just out of curiosity, how many cups of salt are people adding per gallon to reach 1.025? I know answers will vary, but I’m sure they’re generally in the same ballpark.

I use the hamzas reef "direct salt addition calculator" (https://www.hamzasreef.com/Contents/Calculators/DirectSaltCalculator.php) and measure my salt in grams using a food scale.

According to this calculator, which I've found to be pretty accurate, 5 gallons needs about 800 grams of salt, which according is about 3 cups

 

[Randy Holmes-Farley]

Are you certain it all dissolved?

I don’t see how a bad batch of salt, within reason, can explain what is being reported, but perhaps as noted above, the clumpiness messed with the volume measurement .

Try measuring the alk before tossing it out.

 

[ATXreefer]

Good news folks: with the new bag of salt, I am now reading 1.025 with slightly less than 3 cups in 5 gallons. I’m thinking the clumped up salt in the old bag is the issue (causing measurement discrepancies as well as making it difficult to dissolve?). Although to the visible eye, I could not see undisolved salt.

 

[Randy Holmes-Farley]

If it all dissolved, I’d use the old salt too. I’d just add more to the needed salinity, and measure alk. If alk is ok the salt is likely ok.

 

[Nick711]

Didn’t go through the entire thread, but IIRC the TM hydrometer does not read much higher than the low 1.030’s, so if you added more salt than that you may think you are getting a zero reading when in fact it’s too high in the other direction

 

[EeyoreIsMySpiritAnimal]

Didn’t go through the entire thread, but IIRC the TM hydrometer does not read much higher than the low 1.030’s, so if you added more salt than that you may think you are getting a zero reading when in fact it’s too high in the other direction

That's not how the TM hydrometer works...

 

[Nick711]

That's not how the TM hydrometer works...

Yes, if the salinity is too low, it will just sink straight down and not float (vice versa, if too high - float high). A user could think it’s not working, when in fact the salinity is just too low (<1.021) for it to produce a reading.

 

[fishyjoes]

Yes, if the salinity is too high, it will just sink straight down and not float. A user could think it’s not working, when in fact the salinity is just too high for it to produce a reading.

exactly the opposite - it will float way high in the water
same behavior as when somebody goes swimming in the dead sea

 

[Nick711]

exactly the opposite - it will float way high in the water
same behavior as when somebody goes swimming in the dead sea

Yes, quoted me before I was able to edit, but correct. If it’s off the scale it may just seem to not be working because it’s a tight range of reading between 1.021 and 1.031

 

[EeyoreIsMySpiritAnimal]

Yes, if the salinity is too low, it will just sink straight down and not float (vice versa, if too high - float high). A user could think it’s not working, when in fact the salinity is just too low (<1.021) for it to produce a reading.

This is the exact opposite of what you said/what I replied to...

 

[Nick711]

This is the exact opposite of what you said/what I replied to...

My original post you quoted said nothing about floating or sinking so I’m not exactly following what was wrong. Sorry. Have a nice evening

 

[Nick711]

This is the exact opposite of what you said/what I replied to...

As a point of fact, there is no such thing as a -0- reading on a TM hydrometer. In my first example, I was merely pointing out that a user may think they’re getting no reading because when putting it in the water it would not move (stay floating), meaning it was >1.031. Second post was stating the opposite end of the spectrum which would also appear to be giving no reading, as it would sink completely, meaning it was <1.021. Hope this clarifies, but both posts are consistently stating this, just using each end of the range to explain.

 

[EeyoreIsMySpiritAnimal]

As a point of fact, there is no such thing as a -0- reading on a TM hydrometer. In my first example, I was merely pointing out that a user may think they’re getting no reading because when putting it in the water it would not move (stay floating), meaning it was >1.031. Second post was stating the opposite end of the spectrum which would also appear to be giving no reading, as it would sink completely, meaning it was <1.021. Hope this clarifies, but both posts are consistently stating this, just using each end of the range to explain.

 

[Randy Holmes-Farley]

exactly the opposite - it will float way high in the water
same behavior as when somebody goes swimming in the dead sea

Or better yet, swim in a pool of mercury. Maybe you could even walk on it. lol

Worst is trying to swim in a pool of oil. Straight to the bottom you go!

 

[Nick711]

Tough crowd tonight - but my point stands on the no readings in either directions lol

 

[fishyjoes]

Or better yet, swim in a pool of mercury. Maybe you could even walk on it. lol

Worst is trying to swim in a pool of oil. Straight to the bottom you go!

I once worked with an industrial soldering machine that included a small tub of molten lead. You could float dang near anything as long as it didn't melt or burn!

 

[Randy Holmes-Farley]

I once worked with an industrial soldering machine that included a small tub of molten lead. You could float dang near anything as long as it didn't melt or burn!

Nice!

 

[BeanAnimal]

Or better yet, swim in a pool of mercury. Maybe you could even walk on it. lol

Had a few 1 gallon jugs of the stuff decades ago... It is a shame it is so toxic, because it is a pretty amazing element to play with.

Now if somebody could just help me get this thing apart... I want to see what makes it tick

Actually contrary to popular belief, they don't have any radioactive materials in them - but certain vintages from the 30s through the early 70s likely do have PCBs in the coolant.

 

[KrisReef]

Had a few 1 gallon jugs of the stuff decades ago... It is a shame it is so toxic, because it is a pretty amazing element to play with.

Now if somebody could just help me get this thing apart... I want to see what makes it tick

On top of the fish tank stand?
Actually contrary to popular belief, they don't have any radioactive materials in them - but certain vintages from the 30s through the early 70s likely do have PCBs in the coolant.

I have a Sawsall, but what is that horrible thing on top of the fish tank stand? I don’t recognize the mechanism at all. I’m stumped