I never noticed this before, but while looking at Tetra's website today I learned that there is supposed to be a difference between the white box and yellow box Whisper Air Pumps. The white boxed pumps are not UL-listed while the yellow boxed pumps are UL-listed.
It's interesting on how the cheaper more economical air pump is marketed compared to the slightly more expensive UL-listed air pump. Because the UL-listed pump has all the "features" which aren't mentioned on the non-UL product description.
Can anyone tell me if it's actually worth paying the extra for a UL-listed air pump? I don't know if an air pump is something that needs to be UL-listed or not. After all, it is outside the tank, but many times it is located below the tank. But I always place check valves on the air line - AND YES, THEY DEFINITELY WORK!** I don't know what the differences really would be between the two models, perhaps that one gets tested by UL and the other is not held to that standard. Any thoughts on this?
**After not checking my DIY CO2
lines for a couple months, letting them die out, I removed the bubble ladders from the tank this week and the water was siphoned out to the check valve a few inches out from the top of the 2-liter bottle.