Engtesy 500W Pond Heater, Stock Tank Heater & Submersible Water Heater for Livestock Automatic Thermostat Controller, Non-Conductive Premium Deicer Outdoor Water Heater for Winter

A winter workhorse for keeping water open

Ice is a winter chore I’d happily outsource, so I put the Engtesy 500W heater through a full season across a few real-world scenarios: a 50-gallon rubber livestock trough, a 110-gallon stock tank, a shallow backyard water feature, and a bird bath. The goal wasn’t to warm water to comfort—it was simply to keep it available and ice-free for animals and fish in biting cold. In that role, this compact submersible de-icer proved surprisingly capable for its size and power rating, so long as expectations and setup are sensible.

Design and safety

The unit is compact and housed in a non-conductive casing that fully encloses the heating element. That design matters: it reduces the chance of accidental shock in mixed-use setups (ponds with fish, stock tanks with curious noses) and adds a layer of physical protection if it’s jostled or bumped. The 10-foot power cord is outdoor-rated and feels appropriately robust for farm use. I still recommend running it to a GFCI-protected outlet and using a weatherproof cord cover at the connection point—standard practice with any outdoor electrical device.

There’s no exterior dial—this is a thermostat-controlled, set-and-forget device. It clicks on as water approaches freezing and shuts off as it climbs to a safe, above-freezing range. You won’t get precise temperature targeting (and you don’t need it for de-icing). There’s also no indicator light. That’s fine day to day, but for troubleshooting you’ll rely on touch (when unplugged and cooled), a clamp meter, or simply observing whether ice forms.

The casing stays cool enough that I didn’t worry about plastic liners or fish brushing by. Still, treat it as a heater: don’t handle it while powered, don’t run it dry, and keep it fully submerged.

Setup and placement tips

Installation is simple: drop the heater into the water, ensure it’s submerged, and plug it in. A few placement tricks improved results across all my tests:

• In stock tanks, set it low and away from walls. If you’ve got a waterer with a float valve or inlet, placing the heater near that mild circulation helps.
• In ponds, position it near the shallow edge where ice forms first, not buried in deep still water.
• For a bird bath, I placed it at the lowest point and used a stone to keep it seated. It’s overkill for tiny bowls, but in a wider basin it maintains an open patch nicely.
• If the surface is already iced over, you can rest it on the ice. It will melt a hole within hours. Don’t leave it perched half in, half out—once through, nudge it fully under.

The 10-foot cord worked for my trough and pond; for the larger stock tank I needed an outdoor, heavy-gauge extension. Secure the cord at the rim with a clip or short length of conduit to protect it from chewing or rubbing.

Performance in the cold

• 50-gallon trough (exposed, windy): In overnight lows around 10–15°F (-12 to -9°C), the water stayed fully open with a thin slush layer forming at the surface edge only in the windiest corners. During the day, it cleared entirely. The water isn’t warm—think just above freezing—which is the right outcome for livestock.

• 110-gallon stock tank (partially sheltered): With lows near 0–5°F (-18 to -15°C) and daytime highs around 10°F, the heater kept a reliably open drinking area roughly two-thirds of the surface, with a film of ice hugging the shaded far edge during the worst mornings. Breaking that brittle edge once each morning was easy; the central area stayed open on its own.

• Small water feature (shallow backyard pond, ~250–300 gallons): I used the heater to maintain a gas exchange opening under a light to moderate ice cover. In teens Fahrenheit, the opening grew to about a couple of feet across and never closed. Fish remained active and safe with moving water around the hole. I would not expect a 500W unit to “heat” an entire pond, but for winter aeration and an open patch, it does the job.

• Bird bath (wide, shallow basin): Even at single digits, the heater kept a clear pool of water. If the bath is metal, place a small tile or flat stone between the heater and basin to prevent hot-spot contact.

Overall, the thermostat cycled as expected. You’ll sometimes hear faint ticking at the outlet as it switches on and off; the heater itself is silent.

Energy use and cost

At 500 watts, it draws about 0.5 kW when energized. Because the thermostat only powers the unit as needed, actual consumption varies dramatically by volume, exposure, and ambient temperature. In my trough setup during mid-winter, a smart plug recorded roughly 6–10 hours of “on” time per 24-hour period. At $0.15/kWh, that worked out to around $0.45–$0.75 per day. On calmer, warmer days, it was closer to $0.20–$0.30.

If you’re in a consistently subzero climate with big, exposed tanks, budgeting on the higher end is wise—or consider insulating your tank to cut runtime significantly.

Durability and maintenance

The casing handled kicks, bumps, and the occasional inquisitive hoof without drama. Weather exposure, splash, and freeze/thaw cycles were non-issues. In hard water, mineral scale built up on the housing after a few weeks. A quick soak in white vinegar and a soft brush restored the surface. Do not scrape aggressively or use acid stronger than household vinegar; the casing doesn’t need to be spotless to function.

A monthly check to clear leaf debris or hay strands from around the heater keeps performance consistent. At season’s end, dry it thoroughly before storage.

Where it shines—and where it doesn’t

• Best use cases: keeping livestock troughs and medium stock tanks ice-free, maintaining a gas-exchange opening in small ponds, and providing open water in larger bird baths. It’s an “anti-ice” tool, not a water warmer.

• Volume and climate guidance: In my experience, 500W is a sweet spot for 40–100 gallons in typical winter conditions and for creating open patches in larger bodies of water. As the mercury drops below 0°F and wind exposure rises, expect the heater to maintain open areas rather than fully clearing large surfaces. Insulating the tank and minimizing wind makes a remarkable difference.

• Limitations: There’s no adjustable thermostat, no status indicator, and the fixed heat output means you can’t “boost” performance on exceptional cold snaps. If you’re trying to keep a tall, narrow barrel fully open in sustained subzero weather, the surface-to-volume ratio and poor circulation work against you; upgrading to a higher-wattage unit, adding a simple aquarium pump for circulation, or insulating the container will help.

Practical tips to maximize success

• Use a GFCI outlet and an outdoor-rated extension cord if needed.
• Insulate the tank (even a wrap of foam board and a lid cutout) to reduce runtime.
• Add gentle circulation if possible; moving water resists freezing.
• Place the heater low and central; avoid contact with liners by using a small stand or flat stone if needed.
• Plan for hard-water cleaning with periodic vinegar soaks.

Pros

• Simple, safe, non-conductive build that’s animal-friendly
• Effective thermostat control—runs only when needed
• Compact form factor fits troughs, tanks, and pond shelves
• Quiet operation; no moving parts
• Solid value for keeping water accessible in real cold

Cons

• No temperature adjustment or status light
• 10-foot cord may be short depending on layout
• 500W can be stretched thin in large, exposed tanks during deep freezes
• Mineral scale requires occasional cleaning in hard-water areas

The bottom line

If your goal is to keep water accessible—not cozy—in winter, the Engtesy 500W heater does the job with minimal fuss. It’s straightforward to deploy, safe around animals and fish, and powerful enough to keep medium tanks and small ponds open in legitimate cold. For harsher climates or larger, windswept tanks, pair it with basic insulation or light circulation, or step up in wattage.

Recommendation: I recommend this heater for most small to medium livestock setups, backyard ponds needing an open patch, and larger bird baths. It’s a dependable, energy-conscious way to fight ice without overcomplicating your winter routine. If you regularly see sustained subzero temperatures on large, exposed tanks and want a fully clear surface, consider supplementing with insulation, an additional heater, or a higher-watt unit.