Instant Ocean SeaTest Hydrometer

Instant Ocean TK-504 First Impressions

Calibrate it, use it.

Make your own by simply boiling some water and collecting the condensate. This one here was much cheaper,& exactly the same as they sold in the store. My only criticism would be that it's a little too dark. Normally that gives the more accurate reading. Used distilled water to calibrate, the screw is located under the rubber cap. Once I adjusted the refractometer, my aquarium salinity read 1. Hate the batteries, but once loaded, it seems to work fine.

• Editor's Impressions Of The Instant Ocean TK-504
• Accuracy [star rating='3.8']
• Build Quality [star rating='3.3']
• Value For Money [star rating='3.4']
• Feature Set [star rating='4.5']

• Instant Ocean TK-504 Features & Specs
• Marine hydrometer: Tests salinity and specific gravity in marine aquariums to help maintain a healthy tank
• Accurate: Precise, full-range readings - accurate to +/- 0
• Ready to use: Simply dunk in aquarium to fill with water, then set on level surface to read
• Easy to read: Clearly marked to show results
• Extra-wide stabilizer base: Two-color scale with a safe zone for simple results
• Manufacture: Instant Ocean
• Item Weight: 0.8 ounces
• Product Dimensions: 6.3 x 4.2 x 1.3 inches