what is your reef tank salinity?
 

I am just wondering what is your salinity? Can reef tank (coral and fish) handle two point (0.002) shift up in one day due to evaporation?

Hi,

I maintain 35% Salinity / 1.026 Specific Gravity @ 80f

It's would be best to keep a stable environment for both coral & fishes, however small fluctuations have not been a problem for me in the past....

Regards, Simon..

1.025 @ 78f

1.0235 @ 78 for my 2 tanks. ATO on both so no variation in salinity.

An ATO is a great investment as your tank will benefit from the stability. Especially if you keep SPS. I run my tank at 1.026

1.024 right in the middle

1025 @ 79F
I use a drip method for my top off - holding tank is above the sump and drip it in at a steady rate with airline tubing. It takes a few days to figure out what rate to have it at, and there is some variation depending on how hot the day is. It is not as good as an ATO, but it works for me and no danger of malfunctioning float valves and pouring fresh water into the tank causing a sudden drop in salinity, I have read a few threads about that happening.

1.025 and i have to lug a 5 gallon jug daily to top it off..the things i do for coral:smile:

sorry, the temp is also 79 degrees f. I have my ac always down about 20c so my heater runs quite a bit in the summer, should be no problem when my new 250w MH arrives next week:lol:

Yes.
see http://www.advancedaquarist.com/2009/6/aafeature