The Puffer Forum

What hydrometer is accurate? My last one sucked. Keep in mind a refractometer is not in my budget.

i bought an instant ocean one that was inexpenive and was pretty much right on. Most LPS carry them

Anything that isn't calibrated with marine calibration solution, may not be accurate.

Buy a used Refracto. I grabbed one for $20.. get it calibrated by your LFS. Yeah yeah.. How do you know theirs is calibrated properly? Go to a store that has a "display only" tank and ask how long it has been running. If it's 2-3+ years and flourishing, they must be right on. Ask if you can calibrate your refracto to theirs. Cheap and easy.

Even box-type hydrometers can be pretty accurate. As with refractometers, upkeep is key. If you rinse or clean the equipment routinely and properly, and check it regularly, you can rely on it to perform for you. But you do have to keep it clean and test whatever you are using routinely.

If you re going reef, you should be using a refractometer. Ditto if you are keeping delicate specimens, whether vertebrate or invertebrate.

If you are running FO or FOWLR housing hardy specimens only, you may likely get away with simpler equipment.

If you do not keep up the monitoring equipment well, even the best instruments will not do the job.

Calibration fluid is cheap. I have a feeling most LFS don't use or carry it.
http://www.bulkreefsupply.com/store/aqu ... fluid.html

I have a strong feeling that your feeling is highly accurate.

Where would I buy a used refracto?

Ebay, Craigslist, Amazon, Reef Central.