Large tank evaporation question

[LotsaTanks]

I have a 300 gallon 5'x3' tank connected to 2 60 gallons with a sump that is about 75 gallons of water. So total about 500 gallons. Evaporation seems to be quite a bit. Up to 4-6 gallons a day. I added about 3 gallons at night and 14 hours later it evaporated. I don't see any leaks, but is that about right for evaporation or should I go crazy looking for leaking that isn't obvious?

 

[Psirex]

That sounds about right, i have a similar setup and evap is ~ 5 gallons a day. A few things come into play.

My tanks are topless and I keep them at about 79-80 degrees.....

posted using alternating currents.....

 

[LotsaTanks]

Ok, thanks for the feedback so it sounds like my tank is about right. Time to set up the auto top off...

 

[iced98lx]

Things that impact evaporation:

velocity of air above the water surface

water surface area

humidity ratio saturated air at the same temperature as the water surface

(http://www.engineeringtoolbox.com/evaporation-water-surface-d_690.html)

I fill my 14 gallon ATO container 1 time every 7-10 days and it's typically never empty when it gets filled, so you're roughly 2-3x my 180 gallon reef. Depending on the footprint of your tank, if there is an airvent over it or a fan and the temp you keep it at that could be completely normal.

 

[dave.m]

Make sure you ventilate all that humidity directly outdoors, from both the tank and the sump areas. It isn't just humidity, it is saltwater humidity and can be very corrosive over time.

Dave.M

 

[Psirex]

Make sure you ventilate all that humidity directly outdoors, from both the tank and the sump areas. It isn't just humidity, it is saltwater humidity and can be very corrosive over time.

Dave.M

Yea this too

posted using alternating currents.....

 

[slief]

Sounds about right. 1 Gallon of evap for 100 gallons of volume is what I usually tell people to expect. I get between 5 and 7 gallons a day on my 700 gallon system. The more you use the AC, the greater the evap too.

Make sure you ventilate all that humidity directly outdoors, from both the tank and the sump areas. It isn't just humidity, it is saltwater humidity and can be very corrosive over time.

Dave.M

Great advice! That was a prerequisite when I built my tank in. I have a 10" very high CFM fan that ducts the air above my tank out through the wall to the outside. It also draws air in from below the tank as well. Big tanks generate a lot of humidity that can damage the walls and cause mold issues over time if not properly addressed.

 

[turbogarrett]

I have a 7'x4.5' tank connected to a 5x2 sump and only top off about 6-7 gallons a week. I keep most of it covered though.