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View Full Version : Frozen water bottle to cool tank?


xlayedoutx
04/29/2006, 06:04 PM
ok I just read on another site about a guy that use's a Frozen water bottle to cool his tank a little when he needs it. Says he just takes the wrapping off it fills it with fresh water, freeze's it, and puts it in the tank when needed. Says he only needs one to keep the temp in check and usally has another ready to go.

My question is, is this ok for the tank. I don't see why it wouldn't be as long as the bottles were clean and had no chemicals on them. Do you think this would work. This guy seems to swear by it.

Bebo77
04/29/2006, 06:13 PM
sure it would but how well it will work depends on the size of the system... i have a 400 gallon system and a frozen water bottle wont do a thing for me...

Rock Anemone
04/29/2006, 06:13 PM
I've done it before, worked great! However my bottles broke after a dozen uses from being chilled and then warmed. I may need to do it again in the sump this summer!

Rock Anemone:D

festus
04/29/2006, 06:13 PM
I would only consider this in emergency situations. Its hard to regulate how quickly it would cool the tank. Also its very hard to regulate when to start cooling the tank. Its just not a very stable way to do things.

I did have an emergency situation a good while back and didn't have frozen water bottles handy. I did have some frozen vegetables in the freezer and they were in plastic bags so I tossed them in.

Figuring the plastic kept the water out of the vegetables I put them back in the freezer. Later when eating the frozen peas we could not quite place the odd flavor in them and wondered until my wife recalled I had put them in the aquarium. I guess that bag had a hole in it somewhere.

I'm still in trouble over that one........... ;-)

xlayedoutx
04/29/2006, 06:15 PM
Yeah thats what someone had said was that it wouldn't work that great on a bigger tank. This guys was a 90 gal. Mines a 75 so I might try this, and see how much it helps.

RobbyG
04/29/2006, 06:15 PM
That would have to be one big bottle! I doubt that even a 1/2 gallon bottle could cool a 75 Gallon tank for very long, maybe an hour before it would melt out. Of course you have no control over how low it will drop the temp. If your tank is at 81 it may drop it to 75 so you could end up with wild swings in your temp.

ajwatson21
04/29/2006, 06:36 PM
what an interesting idea! My water temp is starting to rise because of room temp rising due to the weather. I wonder how often you would have to add a frozen bottle to keep the temps lower though. Also how fast will the temp change? Will it drop fast enough to cause death to fish?

Scuba_Dave
04/29/2006, 06:45 PM
It's an accepted Emergemcy method of cooling a tank
I wouldn't do it on a reg basis
I keep frozen 2l bottles in the freezer
At 240g a small bottle won't do much

xlayedoutx
04/29/2006, 06:47 PM
LIke I said mines a 75 gal and its empty right now. Not even water. I'm filling it up on the 13th so if needed I'll add a water bottle and let you all know how the temp changes.

Gary Majchrzak
04/29/2006, 06:47 PM
The ice method is fairly useless, IME.
In an emergency, direct as many fans as possible towards your aquarium to enhance evaporative cooling.

kypatriot
04/29/2006, 06:50 PM
I make our ice from the RO water, and I know that it is safe to throw a few cubes in. My tank is a 135, so I can throw in 8 cubes before it makes any change at all (I experimented with different amounts of ice)

Sometimes evaporative cooling just doesn't seem to be enough, and this has helped push it over the edge just enough. (lowered temp by 1 degree). By using cubes, I can make it happen slowly by not putting many in at once.

Gary Majchrzak
04/29/2006, 06:59 PM
Still think ice compares to evaporative cooling?
Check out this thread:

http://www.reefcentral.com/forums/showthread.php?s=&threadid=78140&highlight=ice

<a href=showthread.php?s=&postid=528162#post528162 target=_blank>Originally posted</a> by ToddsReef
Conclusion #2: In order to cool Andy's (120 gallon) tank from 88F to 78F by putting 2liter bottles full of ice in the sump rather than using 1 gallon of evaporation you would need 10.66 two liter bottles of ice!!! Glad you brought that up Guy, I hadn't thought about it that way...man, I really appreciate my 2.3 gallons per day of evaporation as I would need another refrigerator to hold the 24.52 bottles of ice each day!!!

Calculations #2:
-Assume that the ice is at 32F and will be melted and then heated to 78F
-heat of fusion of ice tells us that it would take 333 KJ to turn one KG of ice at 32F into one KG of liquid water at 32F. Then to heat the water we would use the specific heat of water to determine that it would take 106.8 kJ to then heat that water to 78F. So per liter it would take 439840.8 J to turn the ice into water at 78F.
-Recall, we needed 8060000J to cool Andy's tank 10F, so we would need 19.55KG of ice to do this.
-Since ice is less dense than water we also have to take into account that we could only put 1.834 liters of water in each bottle to end up with 2L bottles completely filled with ice (otherwise we would have a bunch of broken bottles).
-So as I said above, with 1.834 KG of ice in each bottle at 32F and with time to allow this to completely melt and then warm up to 78F you would end up needing 10.66 bottles to replace one gallon of evaporation!

kypatriot
04/29/2006, 07:24 PM
I don't think there is any doubt that evaporative cooling will remove more heat than melting ice (that's why God made us to sweat).

I use the ice only when evaporative cooling (using fans) is insufficient. I could run my home A/C more, and it would work too, but a few cubes of RO ice are much cheaper.

Of course, if I'm going to be away for a while, I make sure the thermostat on the home A/C is low enough that I won't have a problem.

Also, it is summer when you need the tank to be cooled the most - which is the same time of year when the humidity tends to be highest (especially places like the Ohio Valley). The higher the humidity, the less evaporation you'll get. (I get much more evaporation during the winter than I do in the summer).

kypatriot
04/29/2006, 07:27 PM
Re-reading my post just brought something to mind, and I might experiment with this soon -

I wonder if it would help to run a dehumidifier in the room where the tank is, to get more evaporation. I would still use a fan, but Le Chatlier's principle should apply quite well here. (and I already have a $150 dehumidifer, but can't afford a $1000 chiller)

TOURKID
04/29/2006, 07:32 PM
I had a heater malfunction that brought my temp up over 96 degrees overnight. a water botlle is just about useless. i have a 45 gal tank and I used 2 nalgene bottles at a time. they melt within a half hour and barely took it down a degree

Airman
04/29/2006, 07:53 PM
I used ice in the bottle method for a two week period when I was having trouble with high temps. Then I got a new power supply for my fans and everything was back to normal. I would say emerency use only.

Scuba_Dave
04/29/2006, 08:18 PM
I actually do keep about 10 2l bottles frozen in the summer :)
They are great for pool parties
In an emergency, every bit of cooling helps

Fishfreak218
04/29/2006, 08:25 PM
i did it during the hurricanes last year.. but there is/was a LOT of fluctuation... only do it in an emergency situation.. my tnak was hitting 88degrees

xlayedoutx
04/29/2006, 10:32 PM
<a href=showthread.php?s=&postid=7274136#post7274136 target=_blank>Originally posted</a> by TOURKID
I had a heater malfunction that brought my temp up over 96 degrees overnight. a water botlle is just about useless. i have a 45 gal tank and I used 2 nalgene bottles at a time. they melt within a half hour and barely took it down a degree

Yeah I'm not saying that i'm going to use it as my main source of cooling. Just when I need that extra degree or two. When the fans just aren't doing enough.

Fuegofish777
04/30/2006, 12:55 AM
i for sure dropped ziplock bags of ice in my fuge last summer....it was like 97 in my room...]my tank didnt like it. i have a HOB fuge so it was kind of difficult. luckily im moving my tank tomarow and installing a sump...should make a whole lot more room for ice bags huh? :)

Gary Majchrzak
04/30/2006, 11:00 AM
<a href=showthread.php?s=&postid=7275641#post7275641 target=_blank>Originally posted</a> by Fuegofish777
luckily im moving my tank tomarow and installing a sump...should make a whole lot more room for ice bags huh? :)
Much more importantly: your new sump will provide more surface area for evaporative cooling.

Scuba_Dave
04/30/2006, 12:31 PM
Best method is to make sure your tank will not over heat.
Many times by the time you get home & the tank is over temp it is too late - if the hottest part of the day has already passed (I get home at 6p)

A controller that can beep you if the temp exceeds a cerain temp is great. Some people hook up web cams so they can check on your tank.
I have 100g of water in the basement that helps keep my 125g cool. I also open up 1/2 my canopy in the summer on hot days.
My 3 MH lights are staggered off/on times
I'll be redoing my canopy for a more open design for summer - so I don't have to remember to prop open the canopy

Also upgrading to a 180g show, 130g sump, and the 125g will go on the basement as a frag tank. Than another 75g will be added for summertime only for additional passive cooling

It's always better to avoid the problem before it happens
In 2 years I think the hottest my tank has ever been is 87/88

Also - buy a thermostat/thermometer that records the highest/lowest temp. This will allow you to track the high temps

I run A/C in the summer - just enough to keep the tank cool
Added benefit is it keeps the house cooler & less humid

xlayedoutx
04/30/2006, 02:30 PM
<a href=showthread.php?s=&postid=7277339#post7277339 target=_blank>Originally posted</a> by Scuba_Dave


I run A/C in the summer - just enough to keep the tank cool
Added benefit is it keeps the house cooler & less humid

Yeah I run my A/c in the summer too. Its set to 80 when we wake up in the moring 76 while we're gone, 78 when we get home, and 82 while we sleep. Its at 76 for 5 hours while the lights are on and 78 for the last 3 hours the lights are on.