ATA Hydrometer Needle (floating) (HS-09)

Description

The ATA Hydrometer Needle (floating) (HS-09) is marine aquarium equipment for saltwater setups.

Key Features

• Designed for marine and reef aquarium systems
• Supports the unique demands of saltwater environments
• Durable and reliable for long-term marine use

Using the ATA floating hydrometer to check marine salinity in SG

For anyone running a saltwater or reef tank in Singapore, a hydrometer is the cheapest reliable way to keep an eye on salinity between water changes, and this floating needle type is about as foolproof as it gets. There are no swing arms to jam with salt creep and no electronics to drift; you simply float it, read the needle, and you have a number. We keep one on hand even in shops where a refractometer is the primary tool, as a quick sanity check.

One thing worth knowing here: floating hydrometers are calibrated to a reference temperature, and our marine tanks usually sit warm around 26-27C, so the reading shifts slightly with water temperature. For day-to-day top-ups and water changes that small offset is fine, but if you keep sensitive corals it is worth cross-checking against a calibrated refractometer now and then for accuracy.

Browse the rest of our marine equipment range, and our guides on hydrometer versus refractometer and calibrating for salinity explain when to use each.