A question about temperature and chillers

[visuvius]

Forgive me if this subject has been discussed to death; I used the search function and went through as many threads as I could about temperature.

I've always had trouble maintaining a temperature of under 80 degrees. Everything I'm reading is saying the ideal temperature is 78 degrees and that somewhere in the range of 78-82 is fine, as long as there aren't major fluctuations. My tank is usually right at 82 with a low of about 80.5 and it can get as high as 83.8.

Chillers are pricey. My main question is, do I need a full on 1/4 HP chiller to get to a constant 78-80 degrees? What will happen if I get like a 1/10 HP chiller or something that is made for like a 60 gallon tank? Will I get any kind of chilling effect at all? I mean, I don't need a 10 degree pull down, just a couple of degrees.

I've tried the blowing a fan across the top of the water but it didn't seem to help much. The fish and corals appear to be fine but I'd just be more comfortable with a lower temp.

 

[CaptainAhab]

One consideration might be planning ahead, if you think you may be getting a bigger tank. Might be cheaper to go bigger now.

 

[fishmonkey]

what kind of fans did you use? the heat is most likely coming from the lighting fixture. if you had fans, the most effective way to cool down the fixture is to have one or two fans blowing cold air into the fixture, and one or two fans blowing the hot air created by the lighting out.

to test if the heat is coming from the lights, test the water right before they turn off. then the next morning, test the water right before they turn on. if it is more than one or two degrees, then you will know if the lights are the problem.

 

[melosu58]

that somewhere in the range of 78-82 is fine, as long as there aren't major fluctuations.

I think you answered it right here. The key to temp. is stability. You have your Temp in that range you mentioned and it stays within a degree or two then you`ll be OK. JME

 

[visuvius]

I will try this.

I'd like to use more fans but the problem is I can't find a good way to mount a bunch of fans under the hood. What type of fans are you guy using for this type of application? I'm having trouble finding small mountable fans.

Also, its a 100 gallon tank and I won't be going larger for a while. If I can find a really good deal on a 1/4 HP chiller I'll jump on it but for now I'm trying to avoid spending 500-600 dollars.

 

[bar]

Hi. Well I had/have a similar problem, and it turned out to be the pumps producing heat! I had three pumps running (chiller, skimmer, main) and the chiller was constantly trying to keep the temp down, and was unable to keep the tank below 83°. This was with LED lighting which is virtually heat free. But it turns out that 82° or 83° is not terrible depending on what you keep in your tank. I have mushrooms, a fungia, a closed brain and a butterfly, chromis and two dwarf angels, and they thrive. My temperature is high, yet consistent. An important thing to realize with a chiller is that you need a place to send the heat that it produces. Just like your refrigerator at home, the heat that is removed from the tank is displaced elsewhere, and added to (think increase in entropy from physics class). So many people place their chillers in another room. If your chiller is very close to your tank (i.e. in the same room) you will heat up the room and the chiller will have to work harder, releasing more heat into the room, heating the water, making the chiller have to work again, etc.

Chillers are great but they do have limitations, requirements in setting up.

Bruce

 

[visuvius]

Well, this weekend my tank hit 86 degrees and I just couldn't stand it any more. I went looking for some fans but realized I'd be spending about $150. I figured it'd be better to just look for a chiller. I found a Oceanic 1/4 HP chiller that'd been used for 3 months for $350. It is currently in the process of lowering the temp.

 

[melosu58]

Let us know how it goes. I think you`ll be OK with that.

 

[Telek]

Ok hold the phone here.

Keep in mind that a fan doesn't magically reduce temperature in the tank - what it does is cause an increase in evaporation which causes evaporative cooling.

Taking a fan and just pointing it at the top of the water will do next to nothing, especially if it's enclosed in the head of the tank. Once the air in the head becomes saturated with humidity very little is going to happen. You need to create fresh air flow in that will speed across the top of the water and then exhaust out. That will cause a substantial temperature drop (and substantial evaporation as well) with very little investment.

As an example I have a 70gal SW tank with about 1" between the water level and the sealed glass canopy. I was having trouble keeping it in my 72-78 ideal range (was getting up to 84deg some days). A single $5 3" fan placed in the left rear causes a air flow over the surface of the water and exhausts on the front right where I prop the glass door up just slightly.

I ran the fan 16 hours and my tank went from 84 to 68 degrees and lost about a gallon of water.

So I run it on the same timer as the lights, and this keeps the tank in the 76 +/- 2 deg range pretty much all day.

My point being that a $5 fan can trump a $300 chiller if done correctly.

 

[melosu58]

I dont think anyone is talking about just blowing the fan straight down on the water. I do agree that more water will evaporate. That can be taken care with daily top offs. When I had my canopy I would have the fan blow across the surface and it would do wonders as far as bringing down the temp.