Jump to content

Buried treasure or landfill bound?


Recommended Posts

i was just going through some old boxes of fish tank equipment and throwing away lots of little odds and ends and i came across this floating hydrometer. Are these any good? I can remember using it a few times but its been a loooooong time. Maybe i can put it in the sump permanently? Or the trash can works too, either way.


Edited by xxkenny90xx
Link to comment
Share on other sites

These are the absolute bomb!  Tropic Marin nailed it.  This is essentially the only way a chemist measures density of a fluid. If you keep it clean and don't break it, you won't find a more reliable way to measure. Don't leave it in the water (it'll build up a film and junk that will make it float wrong...that's why you need to keep it clean). Just wipe it with your hands under running water when you're done, dry it off, and put it away.

There's no moving part to get out of alignment (refractometer) or stuck (swing hydrometer), no lens to get bumped (like a refractometer), no pins to get oriented wrong (salinity probe/pen). The only thing that can really mess with it (and ever form of density/salinity measurement) is temperature. But if it's 1.0260 at 79'F, it'll show 1.0270 at 72.5F, so it shouldn't really change your numbers much unless the temperature ranges wildly. Most refractometers and salinity pens post a 0.002 inaccuracy (plus temperature variation), so when it says 1.026, it could be 1.024 or 1.028, you can't be sure. But this thing has an accuracy of 0.001, so you know it's between 1.025 and 1.027, plus the resolution has an extra decimal place than most other devices.



  • Thanks 1
Link to comment
Share on other sites

Ok ok im convinced. I tried it on both of my tanks and it seems spot on. I'll start using this instead of my refractometers, at least until I break it (is there anything inside of it that'll nuke my tank when I break it?). I wonder what other old equipment I've tossed that is actually better than my new school stuff.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...