make sure the adaptor has sufficient current to unleash the "power" of the 80mm dc case fan
After my bigger adaptor blown, I happen to be at china town and bought a small adaptor from a shop at the complex with many tour agency. That woman owner told me "no need big adaptor.. small one can work liao!" ... walao forgot all my electrical knowledge and bought it cos it was cheaper. Sure the fan works if only 1 is connected to the adaptor. Forgetting I'm using a smaller adaptor, try to connect 2 fans to it and both fans run slowly. There goes my tank temperature...shooting up to 29 degree with 4 fans without T5 on!! , but powered by 2 small adaptors. That's bad. Took me a while to figure out that I need one that has more current .
Replaced with 2 adaptors that can support 12V and 500mA and 1200mA lately and tank temperature goes down to 27 degree without T5 on and almost 28 degree with 5 x t5 on. Lesson learnt.