hygger Aquarium Chillers Fan, Fish Tank Cooling Fan,Quiet Aquarium Cooling Fan Equipment with Adjustable Speed Controller, Suitable for Up to 60cm Freshwater Saltwater Tanks(3-Fan Head)

ExcellentTemperature went right down from 29c to 25cAn they can run 24 ,7At different speeds

After taking a whole 4 minutes to set it up it was spinning away and I honestly think it is very quiet, yes you can hear the 3 fans going but not that loud it is quieter than the stand fan that I was using and it works well it dropped the water temp by 1 degree in around 40-45 minutes so not a rapid drop which would be detrimental to the fish.I really like it carnt fault it at all the controller is very simple to use and it can be on for up to 12 hours. I have read people saying it's not on a daily timer but how do you know if the water is going to be to hot or not. Very impressed and for the price a bargain.

I didn’t hold out much hope for these fans when they first arrived and was going to send back as the fitment opening is too narrow for the edge of my tank (not even as wide as my little finger).However, in desperation with rising tank temperatures for my axolotls, I managed to rig something up across my tank using a little shelf we had and found they actually work really well at keeping the temperature down - far better than a large fan I had aimed over the top of the tank!Be aware that the fitting is rather narrow though and there is absolutely no way to use brute force to make it any wider! They fit perfectly on this shelf, which is 12mm wide.I bought the 3-fan thinking I could probably add to it if I needed, but you can’t add more to the same plug (there is a connector that all the fan plug in to).It’s useful to have a timer and speed switch that you can choose to use or remove too. The timer only goes up to 12hrs and you would have to keep restarting it if you use this function.

Tank: 19l.Fans on second highest setting.No styrofoam on sides of tank, so I'm assuming this could drop the temperature further if there was.Ambient temperature 23 degrees Celsius.Tank temperature 19 degrees Celcius.Just thought this might be helpful to anyone looking to rescue their axolotl from the heat.19l is far too small for an adult axolotl but for a budget emergency heatwave solution while at work (and when you can't use frozen bottles of water), this is very decent.Consider it -4° on your room temperature using these at almost max speed.

I was in desperate need of cooling down my axolotl tank, as it had gone up to a dangerous 23 degrees and bottle of frozen water just didn't keep the temp low enough. I got the 3 fan version and with the use of a bottle of frozen water and all 3 fans working the temp went down very quickly to 17 degrees.The added bonus of having a timer so I can be going during the day and be off at night, or vice verse.Really wish I'd bought these a few weeks ago.Defined recommend to keep the temp down on tank.

Keeps the tank a couple of degrees cooler when I need it.

OK does the job

These worked a treat. I keep cichlids and with the weather the tank temperature was 30c without the heater being on. I received these last night and by the morning the temp had fallen to 26.5cOnly downside is the maximum thickness of the glass that can be accommodated. Had to clamp thinner wood to the back of the tank so the fans would fit.