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Aquarium Advice Apprentice
Aug 16, 2005
Chicago, IL
I have a 125 gallon tank. with about 60 lbs. of live rock 1 yellow tang 1 goby. 2 anemities, 1 fire shrimp and metal halide at 150 watts 14k. water temp is hovering around 82 degrees. I have had this tank for about 6 weeks now. my question is do I need a chiller ? I get a different answer every time I ask different pet store owners about the need to get a chiller. I do plan on adding about another 15 lbs of live rock and about 4 - 8 more fishs. I get answers like you only need a chiller if you run hot ? what is hot and what is not hot ? Chicago is having a hot summer and I think I shouldn't have a problem in the winter keeping this tank cooler

I'm no expert on chillers, but I do know that 82 degrees is not too bad. The question there a big swing from day to night? Big swings are what hurt the most. I would also add that unless it hovers around 84 or 85 or higher, you might be okay.....again, assuming no big swing changes from day to night, etc.
I have almost the exact same setup, and I have a chiller. But Dr. Nate is right if temp between day and night varies by 3 degrees or more I suggest you get a chiller.
seafan ,.. did your tank varied by 3 degrees,... i that why you have a chiller ?

I have a chiller because it is impractical for me to keep my whole house as cool as it would need to be in order to keep the tank at a reasonable temperature. My temps hit 86-88 during the day and I had animals (corals mostly) that were starting to stress from the high temps. I keep the tank between 80 & 82 now.
Two reasons why I got a chiller:
1. My temperature varied by 4 degrees it was 84 degrees during the day and less than 80 at night.
2. I couldn't sleep with the house that cold. I had to keep the A.C at 71 degrees.
Seafan,.. Wow ! I didn't think that a tank can go through that much of a change in temp.
I am going to get a digital temp checker and check the temp at night and day.

Although the specific heat capacity of salt water is enormous, so is the amount of heat emitted by mh bulbs.
82 degrees is fine. Just get a heater so the temp at night stays at 82. If youneed a chiller it is hard to beat the pacific coast models. buutt if you are not at 84 or above you are fine. Just keepthe stock levels down with the higher temps since dissolved oxygen levels get less with higher temps.
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