Lids on tank or no lids?

[blancoh2o]

I have an 80 gallon salt water tank with 2x250w Mh lights plus 2x75w VHO lights. I discovered today that my surface temperature is about 5 degrees warmer than my sump temp.. I have put a couple fans in my canopy today to see if that controls the temp better. My question is: should I leave the acrylic lids off or should I leave them on? I don't have any jumping fish problems, but I thought the lids may keep my corals from getting too much light. Well, the light didn't get them, but the temperature sure did. I never checked the surface temp thinking that the temp should be same throuhout the tank with the flow that I have---WRONG. What do you think about the lids? Do they just trap heat or reflect it out?
Thanks in advance,

 

[MT79]

IMO, I would remove the lids. This should allow more air to contact the water surface consequently absorbing and carry off heat.

 

[kellane1]

lights

IMO the only concern i would have, would be, the evaporation factor and the fact that you are going to expose your lights to moisture and salt, the first which is just dangerous if they short and the second is that salt is very corrosive to metal
kell

 

[MT79]

Evaporation will most likely increase, that is definitely something to watch for. As for lights and corrosion, maintenance and common sense should take care of that.

 

[cj10488]

I would run the tank without lids.. The lids trap in the heat as well as the co2.. Removing the lids will help with more oxygen in the tank and help with a fluctuating pH as well as help alot with temps.. FWIW I run my tank without any sort of lid..

HTH<
James

 

[Gauge]

I run my tank lidless (cuz I broke mine). My lights are pretty much exposed directly above the tank. As long as you're careful it should be alright.

 

[sw-addict]

I have run my 120 with lids for a year with pc lighting so I don't know about the temp problem. I have removed my lids and now instead of 30oz of water a week it evaporates 1 1/2 gallons a day and my lighting looks great again. It also has reduced the haze on top of my water.

 

[pipermurphy]

I too run my tank lidless, I made my own hood and placed the MH's & actinics 12" above the water line. I use about 1 gal a day in topoff, but feel that a constant influx of RO water to replace evap water can only benefit the tank. Doesn't hurt for sure.

 

[blancoh2o]

thanks

things are looking up
My Gornipora is now extending it's polyps and so is the Xenia.
I also noticed that the green haze algea has a much slower rate of buildup now.
Thanks for the advice everyone...
Now time to rebuild the coral inventory.

 

[pecan2phat]

Okay, based on the above answers, I would say no lids is the choice. One question though, without a lid, will the heat rise from the water if your room temp is 10 degrees lower than the water temp?
What I'm trying to say is: will the tank have a hard time staying @ 79 degrees if your room temp is 68 degrees? (with no lid of course)
Should I invest in a higher wattage heater?

 

[Biggen]

will the tank have a hard time staying @ 79 degrees if your room temp is 68 degrees? (with no lid of course)
Should I invest in a higher wattage heater?

It is possible you may need a bigger heater. Although yours isn't as extreme of a case as mine.

I have a 40 gallon in my store (sans the lid and with a sump) and the store is unheated at night. During the winter, it easily gets into the 50's in the store. If it is real cold outside, it will get into the high 40's. I keep a 300w heater in the sump and it easily copes with the outside temperature change. In fact, there are times when it is too warm in the tank.

As you can see, my heater is way oversized for my tank. However, I felt that because of the vast temperature difference I would need something large. I don't think you will have a problem since you building isn't as cold as mine.