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 Final Thoughts
Good price.
Simple to use, but if there are any air bubbles the results will be way off. The instant ocean hydrometer will always be right. 026 with the new Aquatic Experts fluid. Now its easy to make sure I have the correct amount of salt in my aquariums. Looks to provide very accurate readings. Easy to use, easy to clean, easy to read. My only criticism would be that it's a little too dark.
Overall Score
4.2
(426 Points)

- 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
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