Temp? - What's too much?

[JeepTJ]

[Okay, so yesterday wasn't HOT, but I noticed the temp on my tank heading up to 83, so I pulled the plug on my halides. Here's my deal:

75G display, 30G fuge
Display has 2x110w VHO Actinic (7:45a-8:00p) and 2x250w MH 10K Ushio (working up to full day, but is currently around 2:00p-7:00p).
Fuge has 1x18w Jalli something PC (24x7).
2x150w Heaters, set @ 78
4" fan at each end of canopy (blows out) wired to run with Halides.

I keep the house's thermostat programmed with 75 for the A/C and 72 for the Heater. The room with the tank can run hotter than the room with the thermostat, but only around 2 degrees.

First, what's a critical temp? I'm shooting to be between 78-80, but it looks like I'm already heading north of that.... Anyone with more experience with these components, timings and such want to chime in with some advice to configuration?]

 

[jfkammer]

[We had critical results at above 84. My tank yesterday also hit about 81. We do have a chilller hwever, it did not turn on yesterday. HMMMMM. I'll have to watch it. It is set to turn on at 80.]

 

[Rick]

[Ed,
Right now you should turn the fans so that they both blow into the canopy from the outside. That will cool more and the fans will last a lot longer. And if you have an open back to your canopy where your sump is? Put a clip on fan blowing into the cabinet and another one blowing air into the sump. Try that and see if you do not get more cooling. This is also going to add to your evaporation amount, but evaporation is cooling.]

 

[Jacob]

[I agree, turn your fans around to blow in. That will push out more heat then it can pull out. Also, depending on what species you are keeping 81-82 is bad at all. Many of the worlds natural reefs are warmer than that.]

 

[kwl1763]

[82 isn't bad at all. Mine routinely hits that in the summer. I've seen some stay at 86 with no issues. I would reccomend not going over about 83 or 84 at the most. As with anything stability is as important as the value. a 76-82 swing would be worse than an 82-84 swing in my opinion.]

 

[JeepTJ]

@Rick wrote:

[Thanks for the quick responses! I'd seen the tank at ~81/82 and hadn't worried, but when it got close to 83, and wasn't near the end of the halide cycle, I was a bit worried - the only thing in there is snails, hermit crabs and a little conch - but I was worrying more about the future and summer...

I'll definitely try turning the fans around to blow into the canopy. That should be a piece of cake with how I mounted them in there.

Also, the fuge is located in the stand beneath the tank, and I've got a temp gauge in there, and the air temp in the stand was running about 84...

I'll see what effect swapping the fans has, and then maybe add one to the sump. Thanks!]

 

[handlessangler]

[i have i window ac unit in the living room with the tank but have not turned it on yet. but the tank tempature is creeping near 80. Last year i hit 85.]

 

[Tommy Tucker]

[Do you take your water temp in the sump, at the top of the tank or the bottom of the tank?]

 

[crash519]

[The topic of fans blowing in or out is brought up often and there is no correct answer. Fans blowing cool air in does work great provided it has somewhere to go. Once the static pressure in the hood increases, the fans essentially quit moving air. The same can be said for pulling the hot air out. If you have plenty of ventiliation in your hood, pulling the air out is more efficient.

I've got a clip on fan inside my hood blowing across the top of the tank. I was having problem maintaning a constant temp with the fan blowing then the heater coming on. I bought a Ranco dual-stage temp. controller and put the fan on one and heater on the other. That was two months agao and I've yet to see the heater come on and the fan is normally off, even when the halide is on :shocked: My tank is now staying around 81. That was probably the second best investment I've made so far.]

 

[JeepTJ]

@Tommy Tucker wrote:

[The two heaters have temperature gauges that are located in the sump - so heating is based on sump temp.

The temp gauge I use for the display tank's temp is located about 3" under the surface on the back glass of the display tank.

All three tend to be pretty close to one another in their readings, however. Maybe that means I'm getting pretty consistent turnover of the water?]

 

[melev]

[I try not to ever go higher than 84F with my tank. But I do feel quite comfortable with the tank running at 80 to 81 on a daily basis. When it gets to 83.5, I begin to sweat.

You can put a fan blowing down over the refugium/sump area, to help bring the temperature down in the display. I've never used a chiller, and fans did the job nicely.

For the past week, the window unit in the fish room has been off. Yesterday and today, I have the doors and windows open to bring in fresh air, and the tank is doing well. Two fans blow across the surface of the water during the lighting period.]

 

[Rick]

@crash519 wrote:

[I have to disagree, blowing cooler air into the canopy is going to be more efficient that trying to pull it out. No canopy is airtight, which is the only way the fans would stop pushing air in. And if that was the case, they would not be able to push any air out either. And if you push cooler air in through the fan, you are going to keep the fan motor cooler and cleaner, which will help keep it running more efficient.]

 

[JeepTJ]

@crash519 wrote:

[My hood/canopy is fully enclosed on the front, sides and top, but the back is fairly open. With this setup, do you think it's more efficient to operate the fans both blowing in, both blowing out, or maybe one in and one out? The fans are arranged so the airflow is more directed to pull from the halides, rather than the surface of the water.

On the second part, I'm confused. You've got the fan and the heater controlled by a temperature monitor, but neither is being activated, even with the halides on? What's the ambient temp of the room, and how enclosed is the canopy/hood you're running?]

 

[SandMan]

[

that's how mine is set up.

both blowing in, in most cases, is best.]

 

[Jacob]

[As the firefighters on the board can tell you, blowing air in is more effective at clearing heat then sucking air out. That is why to clear a smoke filled house or building, firefighters use fans to blow air in. That pushes the hot air and smoke out so they can see inside and make reduce the interior temp which makes it safer for them to be inside and harder for the fire to burn. Trying to suck the smoke and heat out would yield almost no result.]

 

[mwolek]

[

Right result wrong reason...Fans blowing out remove the heat much better then pushing air in. People rarley have enough intake for thier fan if its sucking air out and canopies are poorly designed for good ventilation (a large open back is useless for sucking air out).

By turning the fans to blow in however, we blow air across the surface of the water. This gives an evaporative cooling effect. This is the same reason you feel cold on a hot day when you get out of a pool. The water evaporating off your skin cools you off.

The other big benifit with pushing air in, is that we don't suck as much salty air through our fans, and they will last a whole lot longer.

Yep, good flow and turnover should get you the same temps all around

You'd be suprised how much heat comes from under your stand (if thats where everything is). Consider venting that too.




I'm almost scared to get a thermometer

Tanks were so much easier to keep stable temps up north....and the basements!!! I miss my basement

For now I try and keep my house mid 70's all year, probably not the cheapest way to go, but I have 3 large tanks too.]



Edited By mwolek on 1109034163

 

[JeepTJ]

@Jdaddy3boys wrote:

[Okay... So I'm no thermodynamics engineer, but I reversed the fans last night. Of course, by the time I got home and got time, the tank was in moonlight - but I've noticed the past few nights the tank didn't really reduce in temp overnight much.

Well, fired the fans off, and within 2 hours got a 2 degree drop (81 to 79). Woke up in the middle of the night (sick baby), and saw the tank's heaters were cranking to keep the tank at 77. Okay, so blowing in kicked blowing out's behind.

I'm thinking about tieing the fans into the VHO timer, rather than the Halide timer, so the fans can run a bit longer. And then also getting a clip-on for the stand/fuge as an emergency chiller if needed.

Anyone think I should have the fans/heaters hooked up to some sort of controller? Do they make a more cost effective temp-only based controller, versus the major investment aqua/octopus things?]

 

[Rick]

[I know you can get a dual stage controller that will turn your fans and heaters off and on depending on the tank temperature. I know someone on the board is using one of these products, maybe they will jump and let you know the brand.
I know there is this Medusa brand, but I thought there was one that was a little cheaper.
Medusa dual stage controller]

 

[waterbeing]

[Bret/Crash519,

Could you provide any info on the Ranco dual controller that you referenced above? URL/cost,etc to compare with the medusa/others.]

 

[Ptt]

[Quangtam7,

What brand/model of temperature controller are you using?]