Decreasing water evaporation

[chase33]

I have a 120g tank and lose at least 2 gallons of water daily, maybe more. I have a canopy that is open in the back, and a 40g sump. I have two 175w MH lights which stay on about 8 hours a day, two 110w VHO actinics which stay on about 10 hours a day, a 75w light for the fuge that along with the lunar lights, is on when the actinics are off. Is there a way to decrease the amount of water lost to evaporation?

[Phyl]

Evaporation is the single greatest resource you have to fight off summer temperatures. In the summer we evap roughly 6g a day and that helps to keep our temperatures stable.

As hard as it is to believe, evaporation is your friend. Finding a good top-off solution (www.autotopoff.com) would be to your benefit.

Anything you can do to prevent evap (lids on your tank/sump) will likely cause trapped CO2 which could suppress your tank pH.

Probably not what you want to hear... I resisted it as well. Since adding the fan over the sump, which of course increased our evap even more, I've been able to get rid of the chiller. It's much cheaper for us to add water!

[lando]

While evaporation can be a pain to replace, it is a good thing. As mentioned above, the addition of clean FW can be a good thing for your system. I top-off about two gals/day as well.

[roka64]

You could run your lights less. The heat would not cause as much evaporation.

[Devilishturtles]

I agree with everyone else. 2 gal a day really isn't that much. An auto-topoff maybe something you should look into if you don't like doing the topping off.

I evap about 3/4 a gallon a day in my 45 gallon.

[chase33]

Thanks everyone. I will now look at evaporation as a plus. Funny, I just created a post for suggestions of auto topoff systems. Please reply to the question on that post.

Phyl, are you the same person on NJRC?

[melosu58]

I agree that your evaporation question is not that uncommon. I have close to that amount myself.

[Phyl]

Hi Chase! Yes, same person!

John's the house expert on the ATO so I'll wait for him to get home to answer your question about the 2 limit unit (which is what I believe we have).

[boges_au2006]

hi all quick question. a lot of people say they top off with just a bit of clean fresh water in the tank? is it really ok to do this??
my theory was that when water evapourates i wouldve thought the water would evapourate and the salt would kind of remain behind. (eg the salt lake :P) is this true? in this case u would top off with FW. however i told my lfs this and they said no use SW? what do i do?

[chase33]

Originally Posted by boges_au2006

hi all quick question. a lot of people say they top off with just a bit of clean fresh water in the tank? is it really ok to do this??
my theory was that when water evapourates i wouldve thought the water would evapourate and the salt would kind of remain behind. (eg the salt lake :P) is this true? in this case u would top off with FW. however i told my lfs this and they said no use SW? what do i do?

You top off with FW. You'll notice when you do your salinity level comes back to where it was prior to evaporation. As you stated, the salt remains and only the water evaporates.