Penn-PlaxCascade Mini Fish Tank Heater – Fully Submersible – Great for Freshwater and Saltwater Aquariums – 4” Length – 10 Watt

Great little heater.

Good little tank heater, but if my Betta were to rest on it too long, he’d cook! It also doesn’t always keep the water the right temp, sometimes it’ll dip to 71 and then the next day it’ll be 77 again... not bad though for price

This said it was “mini” in the description but it was anything but that. It also doesn’t have any sort of temperature guage so there’s no way to know how much it’s heating your tank. Returned mine asap. Got something better for the same price.

heater quit working after 1 wk, was waiting for a replacement ?? still have not received. dr kal

I've had this mini heater for my 3 gallon tank for six months. In the last few months the temperature of the water has risen to over 90 degrees. My betta fish seems to be suffering, lethargic, and hiding and I attribute it to the heat in the water. Normally a betta needs a controlled temperature between 75-80 which is what this product claims to maintain. I've disconnected it and asked for a refund. I wouldn't recommend this product to anyone.

This thing heated my fish tank to over 90 degrees. I did not make any adjustments to the temperature, just put it in the tank and my fish died within 24 hours.

I like this heater because it fits my tank which is too small for other heaters. it does heat up the water bit more than it advertised. The only problem with this heater is you will not know if it working or dead as there is no led light to inform us.

Works well in a 3 gallon tank

deliver on Dec 28 2017 stop working Jan 26 2018a complete waste of my money.

used in small 12L tank, over heated tank and started to swell around the heating element, had to remove from tank as did not trust it

Keep 3 gallons tamk at 80°F, started to swell too. Not satisfied. Better with my Marina mini 50w. Much bigger but adjustable.