Salinity meters/hydrometers
 

Anyone else have trouble with salinity meters? I have 3, all read differently, I bought a glass hydrometer and checked it on RO water, it read 1.003 .I used the three different hydrometers on my tank water and got readings of 32ppt or 1.0235, 37ppt or 1.0275, and 36ppt or 1.0265. My glass hydrometer measured the tank water at 1.029 or 39ppt. That's a rather large range of readings and leaves open some potential for trouble. I didn't really want to have to spend the bucks on a refractometer but I am thinking it's the accurate way to go.

Do I have other reasonable options?

Douglas

And before anyone asks yes they were all soaked in RO water for 24 hours

I just went to a refractometer and am amazed well worth the price.

Refractometer - THE ONLY way to go! Well worth the investment and you may be able to find one used for half the price!

Refractometer hands down!! You can get them fairly inexpensive if you look around.... like $40. $40 to keep hundreds or thousands of $$$ in live stock alive is worth it to me.

BCOrchidGuy....... I am a cheap SOB :) But I think my refractometer was well worth the cost. My hydrometer was showing 1.023 and my refractometer showed it was really 1.031. Wow......

Well, considering the cost of the IO one I have, the Coralife one and the Red Sea, plus the glass one I could have bought a refractometer. I guess that's next on the shopping list.

Thanks for the replies folks

Certainly refractometers are easiest and fastest but a clean, calibrated and appropriate hydrometer is more accruate. To be clear I mean a long glass cylinder hydrometer, not the plastic swing arm type found in Capt. Crunch cereal boxes.

Are you reading the glass hydrometer correctly? Make sure you are reading at the lowest level of the Meniscus.
http://en.wikipedia.org/wiki/Meniscus

What model of hydromter are you using? It will be somewhere on the paper within.

Yes reading from the bottom of the meniscus, I think it is a coralife but the paper insert must have moved because it was floating higher than it should have been. Not a big deal I know you need to compensate on them but the plastic ones are all over the place with the readings. Oh and one air bubble can screw up the arm on the plastic ones as well, make it read wayyyy higher.

Douglas

If you suspect the paper has moved in any hydrometer, chuck it out. Useless.

Any good glass hydrometer will have a green or red mark on the inside of the glass that matches same mark on the paper. If they don't line up then the paper has moved. Chuck it.

Chucked !!! with extreme prejudice