Tetra Pond De-Icer, Winter Survival Solution for Fish

I ordered this the day before we were expecting a hard 3-day freeze. My 800-gallon above-ground fish pond ices over easily, so this was one of those last moment orders. It's not a water heater but it did keep the ice from forming around it and my teenage goldfish loved it! During the freeze they huddled up under it and would frequently swim about the pond in the very cold water. Usually they just paddle in place, not robustly swim about. So far as de-icing, it worked great. The surface of the pond has thin ice, but the area around the de-icer was ice free. This unit has a nice 15-ft electrical cord, but I used it with an outdoor heavy-duty extension cord and an outdoor waterproof extension protector that snaps tightly around the fittings. Works like a charm, and I don't have to worry about blowing rain or ice causing a short I do not like the shape and it's light gray color. It floats on top of the water and looks like a ginormous gray tick. (I kid you not.) I have no other description for it except that if you squint your eyes, it might look like an ugly piece of floating gray plastic. But, hey, it works, so no point taken off. I gave 5 stars for overall, easy to use, and easy to install, and 4 stars for value for the money. The latter is because it runs up the electric bill at 300 watts. That's a bit extra on the electric bill for 72 hours straight (or longer), but compared to other de-icers, this is considered low wattage. One side note: I didn't allow my unit to float about freely, which it will if not secured. I secured my de-icer between two rock outcroppings so it wouldn't float around. IDK if it's designed to be a "moving" de-icer, but i made it stationary so the goldfish could huddle beneath it. They seemed to like that. If you're looking for an affordable de-icer with reasonable wattage, I recommend this unit. Some people use a temperature sensing cube Thermacube, but I prefer to disconnect the power cord when not in use.

I have a 14x12’ foot pond. This winter in Massachusetts, it completely frozen over, despite my aeration. I placed this on top of the pond and overnight it thawed through 5” of ice. This thing is great. It’s getting down to 2 degrees each night and the hole is going strong. Will be using this every year!

I've had this pond rock heater for a few years now. It is still going strong. This photo was taken after 8 inches of snow had fallen and several days of single digit temperatures. We had some nights with -5 windchills. My fish love their rock!

This little heater rock is a great value, doing its job in the harsh Minnesota winters without pulling large amounts of electricity. We use this rock heater to keep a hole open on our pond throughout the winter to release the gas that would be trapped by the ice. The rock works great keeping a small area open throughout the winter, when it gets really cold (negative temperatures) the heater can't keep up and will freeze into the ice but when it warms back up it breaks free again, because the top is not heated it will create a little crave for it's self in the snow, which works well. The plastic top isn't the best and we have gotten water in it before which affects the buoyance, which then we just replace the unit due to the low cost, which is why this heater gets a 4/5 stars. For the value of this rock heater you can't go wrong.

The heater failed after one year, dried and stored indoors in a climate-controlled environment in Summer). The bottom rusted and the rust pushed it out of the plastic top piece, allowing water in. See photo and video. The unit shorted and tripped the whole pond offline, thankfully not killing any expensive koi. This is a most egregious manner of failure and after only one year, versus the three year warranty. I asked for a refund versus a replacement as I already replaced the heater (was needed immediately). I also did not wish to send the unit back at my trouble and expense - the picture and photo really do tell the tale, in my opinion and how do you ship it full of water? In attempting to get help in this matter, my experience with the conglomerate (who also make bug spray) was quite bad - calls dropped ‘accidentally’ and put to voicemail multiple times, before ultimately being told that it was ‘impossible’ to refund me (not willing is not the same thing as not able). Recommend not purchasing this product specifically or Tetra products in general.

I have a small round pond, about 8' diameter and 2 feet deep. I also have a waterfall to keep the water moving. Our winter temperatures got below freezing several times last winter. Any time it was going to stay below freezing for more than a day I put this on my pond. It worked great keeping a hole about 2' in diameter even when the temperature stayed below freezing for over a week and it snowed a few inches. The portion of the pond surface that did freeze did not have thick ice. The fish and resident frog as well as my plants survived the cold and I will be using it again this winter! This does not keep the water warm, it just keeps a hole in the ice for air circulation.

Works really well.

These De-Icers only last a couple of years before failing. I have two small ponds, with one De-Icer in each pond. I end replacing a failed unit every other year. I would pay more for a longer lasting product. This is reasonable for the price.

Made for Canadian winter, this rock has kept my little pony from freezing all winter. Temps dipped well below -30 c for a few nights and nothing. This pond heater rocks!!

Ít delivered ơn October 3 , but I just use on dec, 2025. So far it’s work every good

We had an unexpected cold spell this winter, -15C degrees. I put the deicer in my goldfish pond when the temperature dropped below 0. For a week the pond was freeze up completely, except the area of the deicer. As my pond is small, the deicer must have raised the water temperature a couple of degrees, I saw fish liked to stick around the deicer area and a bit more active. I wish this deicer could have a light that indicates when it is working. After the winter use, I thought I'd like to have an update on this de-icer. I found when the temperature was 3 or 4C degrees for a few days, the deicer did not turn off on its own, and raised the temperature of the pond water to 12C degrees from 5C degrees. Not like other similar product that has a light indicator that tells you if the deicer is on or off. So I down grade the rating of this product from 5 stars to 4.

Bien produit, on adre

Worked for one winter only. Purchased in Jan 2022, seal cracked and it filled with water in 2023 and then stopped functioning.