Old Neptune heaters

[dorymarlin955]

I found a couple 25w Neptune heaters, they're brand new but are kinda oldish I think. Anyways I can't find any info abotu whether they're submersible or not, there's a red "water line" right below the green plastic top piece, however idk if that's max or min or the absolute level it has to be at... I don't want to stick the thing under water and get fried

 

[shrimphombre]

you could always submerge the thing and do one of my personal favorites; a canary test with a damsel