Evaporation question

[brett559]

Maybe a dumb question, I didn't get too far in science in high school.

I have 4(ish) gallon ATO container. During the hot summer months, it would last a whole week (Friday to Friday). Now it's running dry after only 6 days. Summers are very hot and dry here; it's (thankfully!) rained a little lately. Does added humidity increase evaporation?

And again, if this is something a kindergartner should know, I apologize.

 

[seamonster124]

Don't think so. My top off is considerably lower in colder months.
Have you changed to halides? Increased temp? DT level increase? Leak?

 

[Dmorty217]

Less moisture in the air in the winter time so evaporation increases

 

[outssider]

the less the humidity, the more evaporation. You should be experiencing the opposite that you are.

 

[brett559]

I did raise the temp a little to compensate for the winter. That's probably it.

I'll just add a little each Monday. and top her off on Fridays.

Thanks!

 

[ca1ore]

Evaporation increases with temperature and the movement of air across the surface; decreases with rising ambient humidity. That's why evaporative cooling works so well in places like Arizona where it's hot but typically not humid. My ATO reservoir is season agnostic. Summer Heat is offset by higher humidity.

 

[jmm]

The key word here is "relative" for relative humidity. If you are bringing in 50% humidity outside air and heating it, you will end up with, let's say, 40% relative humidity inside. Add to that, the heater may be putting out warmer air than room temperature and if that is felt by your tank, the relative humidity of that air can be 35%. This causes more evaporation than the air available in the summer (which is probably 50-65%). Thus most tanks evaporate more air when the heater is on than when the air conditioner is on. Mine definitely does.

The complication to easy analysis is that the tank, especially in a small room, influences the humidity of the room. This makes the above analysis somewhat complicated. Your situation will vary. But one thing is sure: it will be different if the air is heated than when it is cooled by your environmental control.

Do you ever get "shocked" from walking across the room and touching something metal? This usually happens in the winter and is a sign of low humidity as is dry skin.