K&H Pet ProductsPond Heater for Outdoor Ponds with Fish, Thermo-Pond 3.0 Deicer Keeps a Hold in the Ice for Oxygen Exchange for Live Fish, Energy Efficient, Safety Listed - 12in Black 100W

The media could not be loaded.  Several years ago I had purchased an agricultural water warmer and it kept tripping the circuit breaker, so I just kept my fingers crossed for the goldfish in our little Michigan 3 ft deep pond near our door. I decided to try again in 2016, purchased this one. It works great! In below zero temps we have fountain water flowing freely. I have the pond pump on also and this deicer sits around the above water extension on that pump. Right now there is quite an ice structure surrounding it, but the water underneath is not frozen! There is a stiff screen on top of the pond to allow our farm cats to access the water fountain in the winter, and before our latest polar vortex froze the snow cover on the screen, the fish were visible. I have an indoor remote that will shut off the plugin when the weather isn't freezing, making this a breeze to operate.My only problem with the pump is that upon placing it in the water this year, it had taken on water (I hadn't noticed last year) and wouldn't sit evenly. I drilled a hole and drained the water out, which took patience, then sealed it up with aquarium glue. Working GREAT at the moment!I'm very pleased with this product, as it easily solved a problem for us. The 5 star rating is deserved even with my do-it-yourself repair after several years.POLAR VORTEX UPDATE! My approximately 6 ft by 3 ft kidney shaped pool is still unfrozen with running water from the pump extension just above surface level. Temperatures have been in negative single digits for 2 days, double digit negative with wind chill. Very impressive deicer indeed!

This one works great there's no ice in the middle or around the edges when the pond freezes

Purchased this last November to be a less-power-using alternative to the floating pond deicer units I'd used previously. In principle, this seems to be of good design and sturdily-enough built.Full disclosure, we had an especially brutal winter here in New Hampshire with thicker pond ice than usual and upwards of five feet of snow on top of the ice. But, still I was not expecting this unit to fail to perform its basic function and keep a small opening in the ice for gasses to vent.The unit seemed to work well at first, and the first month or so of cold weather, the vent hole was created and maintained. Then, the weather turned colder and we had multiple successive snow storms. We eventually reached an snow depth over the pond where I could see no difference above where the unit was placed, unlike previous winters with other devices. Upon digging the snow above the pond down to the ice level, I could tell that there was still a very small hole in the ice, but the unit had tipped over and was floating, just barely, on its side. I tried to make the hole in the ice larger so that I could reach a finger in and reset the unit. No luck, so I trusted it to keep working and maintain the small hole.Then, just this week, the weather turned warm consistently enough that the snow above pond was gone and the covering ice disappeared. Upon the first full pond inspection allowed since December, I found not only all of my large, prized koi floating on the surface, but the unit had fully sunk to the bottom of the pond, useless.So, the short version: I've found this unit to work at first, then fail catastrophically under challenging, but not unexpected conditions, preventing the pond from properly outgassing over long periods and allowing all my fish to suffocate.

Update.. got replacement super fast. So far working great. I was impressed on how fast they got me my replacement and because of that I recommend purchasing from them!! This is the 3rd one I have purchased since 2016 never before have I had this happen. It arrived Jan 8th and it has already filled with water on the inside making it useless. WTH happened here the other 2 were great. I use them as tank heater for my horses. 10 days and its junk.

this is my second one because I dropped my first one on the concrete pad it didn't look like it cracked but it sank after a couple of days would buy again

Ok. So I found a pond heater at a garage sale and put it in my pond when temperatures dropped below freezing. My fish were happy and swimming around and there wasn't any ice. Well that heater stopped working and the pond rapidly began to freeze solid. Apparently the heater that stopped working allowed the fish to swim in a bath water type environment in below zero outside temperatures. (All the steam around the pond should have been a clue.)Amazon.com shipped this same day and I had in 24 hours. My fish were saved! Thank you.This heater is not as powerful but it's all my pond needs to keep them alive. The ice formed around the heater and the fish stayed under it to keep warm. I'm very happy with this product.

*Update* April 2020: (bought in November/5 mo ago; SW Ontario) *Unit has seemingly failed. We never touched it. Just let it do it’s work/heat. Seems that it was still heating but it has water it and has upended/not sitting Or floating properly. We will call manufacturer. Or maybe just return it.Original post: It is now Feb 2020. This is the first winter we are using it. So far, so good. It has continued to work, having been on 24/7. It keeps a good size area open for the fish. I am hoping it lasts all winter and hope we can get more than one season out of it. So far, it seems to work well and does the job. We have not had sustained long term ice and snow this year so I am curious if it will still do the job but I think it will. Over a few days of bad winter weather, it did not fail us. Based on this: I’d recommend this product. Seems legit/good.

The De-Icer worked well during a recent freeze, but when I removed it 3 weeks later it was half filled with water! I inquired into a replacement only to find out there is a No Refund and No Replacement policy on this item! Disappointing.

I purchased this unit in February of 2023 to replace a different brand. I actually never used it because the air stone had kept an opening so I saved it until this winter. I put it in the pond in Oct, and found it sunk and completely under water by December. I pulled it out, found it full of water. I returned it for replacement, and received a new unit. The new one has held up all winter, and works great. Judging by other comments, it seems as though the units are not all sealed from water very well.

I love that it only heats enough to keep a hole in the ice around it instead of melting the top of the entire pond like the last one I had. (The old one was so warm the fish came up to the top!) It floats almost above the water so I am confident that it wont take in water and sink like the old one did. Uses less energy too which is a great bonus. This heater works so well I bought a second one for my adjoining pond!

For weather reference I am in Nova Scotia, Canada. Bought this in December, it is now February and it's not working. Seems like it started taking on water and not floating properly, perhaps during a flash freeze the seal broke? I don't know. It was still heating the surface and we couldn't afford another one so we kept it going because it was half frozen into the ice. It seems to be heating enough and floating enough to keep a hole in the surface. This weekend it fully stopped working. Disappointed because this puts me in the awkward position of having the deice our fish pond while we order another device. Not getting this one again.