evaporation rate

im cycling and i feel like my evaporation rate is kind of high.It seems like im evaporating a little less than a half cup per hour.That's nearly a gallon over 24 hours and im not even using any lights. Do you guys think this rate of evap is right for a 33 gal with about 20 gallon sump?
On my last tank 80 gal with 20 gal sump and 2 250 watt halides i evaporated about 1.5 or 2 gallons during the day

 

Whats your salinity? if its low, you could have a leak in the tank.

 

evaporation depends on many factors. temp, humidity, lights, water movement ect... id check for a leak though. running a humidifier in the room your tank is in can slow down evap.

 

So you guys think that rate of evaporation is high?
okay well right now my temp is 79.4 and salinity is 1.026 and thats what i mix my water at. i have pretty high flow rate and im not using lights on the tank. Ive looked all around the tank and i cant find water anywhere so i dont think it leaking (that's what i was worried about). i guess all my water cirulation could be causing a higher evaporation rate. i think my return pump is probably pumping about 1200 gph through my tank so the whole volume of the tank is circulated about 30 times an hour

 

Here is a few big factors in evaporation that you may not have thought about.

Is it close to any windows? how open is your top? any fans blowing? how warm is the tank? whats is steady temp? is there alot of water movement?

IMO, i think 5g-6g a week is pretty normal. Especially if you have MH lighting.

 

i evaporate about 2 gallons a day but mine is a 65 gallon. Evaporation is higher in the winter when my house is dry

 

evap for me is 2 g/d on a 120.

 

sounds about right to me. I have a 29 gallon and I top off about 1/2 of a gallon a day. Like others have said, it varies from tank to tank.

 

I get about 1% total tank volume (tank sump ect...) loss per day. A bit more in the winter. Up to 3 or 4% per day is not that uncommon. It depends on a number of factors. I would watch the salinity. If you add back, what is lost due to evaporation/water loss and the salinity doesn't change, then it is evaporation. If the salinity goes down, then you have a leak somewhere.

 

Same tank dimension, same evap rate