K&H Pet Products Pond Heater for Outdoor Ponds with Fish, Deluxe Thermo-Pond Perfect Climate Deicer, Winter Oxygen Exchange for Live Fish, Thermostatically Controlled, Safety Listed - 9in 1500W

This is the 4th pond heater I purchased for my Koy pond in the last 15 years. I lost one heater because water level dropped and unit overheated and burned up. The other two older heaters a 1500W and a 500W worked fine keeping my Koy from freezing untill this winter. Needed more heat because of the extreme cold weather in NEPA this year. So now I have a 1500W on bottom of pond and a 500W and 1000W heater on top floating. All work great just make sure floating heaters do not come out of water when plugged in. My pond is 6 foot diameter with a stream bed and two waterfalls. If it wasent for keeping the waterfalls and water circulating I might be possible for less heating. The pond water is circulated through a filter continusiialy night and day 365 days per year. This is why I need lots of heat for my pond. All work great from Nov thro March

This is my second out door pond heater for my Koi pond. My other unit lasted for 5 years. I upgraded to the 1500 watt model in September. In october when hard fost started I put it in the pond. It worked incredible well and heated my whole pond up to 50-60 and then turned off. After one month of operation only on the coldest nights. It has tripped off the circuit breaker repeatedly. I have always maintaind it and used vinegar and a brush to clean up the build up in the metal. I am very dissapointed. The quality of the build and the reliability of the units seems to have gone down dramatically. Sadly this is consistant with many other reviews. I am reaching out to K&H to see if they will replace it. If they do, I will update my review.

We have a decent-sized Koi pond, and it tends to freeze over for the coldest days of winter where we live. The K&H pond heater keeps at least a small part of the pond to freeze over. The fish congregate around it, so apparently they appreciate it. Ours has been making it through several cold seasons so far, so definitely worth it.

I use 2,(1-750w and 1-1500w) in a 2000 gallon pond. Water stays @ 50degrees all winter in New jersey. I keep an extra in the water in case one fails, which always happens at the worst possible time. 2 years is the best you can expect, i keep a few spare ones, it’s imperative. Bottom line is my fish are older, quite expensive and family. P.S. I’m keeping koi for 30+ years, and this is the best option i have found. Been using K+H for many years. My biggest issue is the cost of electricity!!!!!!!!

I was worried about reviews but so far this has worked perfectly and since i bought the 1500 watt item I was wondering if it would be enough for my pond that is a 15x15 liner and 30 inches deep. not sure how many gallons exactly but if i just leave the thing on all the time the pond does not have any ice except where it flows down the rocks. this got me wondering how much electricity it uses and i attached it to a plug that i can look at from my smartphone and see how many hours a day it is actually drawing power. I have since started to run it 30 minutes an hour and it keeps the pong half clear and half ice. So hope this helps...i believe the device is able to turn itself on and off to keep the water above freezing temperature but if you lift it out of the water while it is on you will see just how hot this thing gets! it actually can burn off the scale or mineral deposits from the pond by doing this. I like this very much but i am now buying the 750 watt item for my small barrel at my main home (the 1500 watt is running at my second home) so far I can not see any way that this would break and i have been using it for 2 months in denver winter. If it breaks i will update if not i typically do not come back to my reviews. oh by the way do not touch this to see if it is working! :) it is crazy hot even in the water but out of the water it heats up so hot it burns off the scale and you can gently poke the layer off or just dip it in the water a few times and the water will knock the layer right off and it looks like brand new again! I use it floating but it can be used at the bottom if you want by simply unscrewing the top part that has the floating device, you can unscrew it without any tools. I like that. my goldfish likes to hang out around the warm water so i make sure to keep it in the middle away from the raccoons reach :)

Works as advertised. My fish pond is in Maine with temps in the low teens or lower every night and this heater has kept the pond ice free so far. My purchase was a good deal but it can be pricey if you don’t shop around. The longevity of it is still to be tested. Update: This the fourth and last heater I'll buy. It has started tripping the circuit breaker after 39 days of use. I'd buy the 2 year extended warranty if I bought another one. I'd be without a heater until a replacement arrived though. Too bad the quality has declined so markedly. The first one I bought lasted two winters. The next two a year each. This latest one just over a month (just past the return window). Photo shows crack in heating element. Causes electrical short.

Works exactly as described. Perfect for a medium size pond to keep the ice open at -20C.

Quit working after 3 months woke up to a frozen pond. Heater tripped the breaker so didn't have fire issues like other reviews