100W Aquarium Submersible Heater Anti-Explosion Fish Tank Water Adjustable by Aquarium Heaters

I bought these heaters to warm up my 5 gallon buckets of saltwater that I buy weekly. I That means I'm using them no more than 48 hours of every week max. Sometimes only 1 day. I have used tbem 3 times. The 1st two times they worked well. But the 3rd time, it fid not warm to temperature. Alsi, they are light weight and do not sink in the bucket.

still working ty

working as intended

Excellence