Fish tank overheating and killing fish

digamma · 4th December 2006, 4:01 PM

I live in Cairns and now that we are in summer, the temps are climbing above 30 and at night, it ain't much cooler. The problem is that the fish tank is constantly above 27 degrees and is approaching 30. I drop in 2 feezer bricks morning and night to cool it down, but they only drop the temp 2 degrees. And by the time I come back, the temp is back up to where it was. What can I do? I'm not willing to spend the 100's of dollars that would be needed for a commercial setup, but would like to keep the tank at a comfortable level and stop the fish from dying.

BTW, I have neons, black widows, white clouds and siamese flying foxes. To date I've lost 4 neons, 2 catfish and a flying fox. I'm not up for losing more stock. Apart from the temp, the water chem is fine and within limits for all the fish.

Deckham · 4th December 2006, 4:11 PM

Yeah, difficult situation.

A few options.
A commercial water cooler costs heaps, but will work.
A portable airconditioner in the room could be cheap-ish and keep the room/tank cool.
A floating 2ltr coke bottle with frozen water (overnight) will drop temps depending on your tank size. I used this method for a 'project' I was working on - worked well.

berek · 4th December 2006, 5:46 PM

I've just purchased a chiller off ebay because I am in the same boat as you. Came home last week and the water temp was 31. Not good for a reef tank. It's a decent brand, Resun, which worked out to be quite cheap. 1/4 hp for $520 plus $30 shipping. LPS had them in stock for $795. They also had the 1/10 hp for $420 where the LPS was $595. Throw in a $60/$90 pump and should be good to go. Thought about room aircon but the running cost would be significantly more.

Agg · 4th December 2006, 7:06 PM

I have similar fish (16 neons, for example) and I have been deliberately running my tank at 29C for the last 3 weeks (to kill off a suspected parasite/illness by breaking the breeding cycle). All the fish have been fine during that time and now we're back to 25-26C again. Are the fish doing anything else unusual, gasping at the surface etc? I vaguely recall something about warmer water needing more aeration..

berek · 4th December 2006, 8:14 PM

Thats another problem. The hotter the water the lower percentage of disolved oxygen. Significantly so. Plenty of online aquaria forums will have all the info you need. Just be aware the 1337 aquarists are just as bad as hardcore overclockers

Strange1 · 4th December 2006, 8:17 PM

Pump up the airstones!
Warm water doesnt hold as much oxygen and the fish usually die from suffocation. Remove or open the lids on your tank, turn up the air pumps and get lots of surface gas exchange going.

Apart from that just ice bricks if you need too.

Agg · 4th December 2006, 8:34 PM

Yup, aeration is no problem here (even with 50+ fish in a 4-foot tank) coz I have a 4 foot airwall and a small internal filter agitating the surface.

But ice bricks etc don't really do much unless your tank is small. If you consistently get >30 temps you probably need a chiller.

Strange1 · 4th December 2006, 9:28 PM

I also remember reading that you can aim a fan at the surface of the water basically turning it into an evaporative cooler...

digamma · 4th December 2006, 10:06 PM

Thanks for the replies so far. Like I said, a commercial chiller is out of the question. I couldn't justify spending that on the fish setup, and the missus would have a hissy fit. And I wouldn't blame her. On the other hand, if I had the moeny, I'd probably do it though. Still, can't afford it. I'll see if i can find freezer space for a coke bottle or 2. At the moment I'm using esky freezer bricks and they are taking the edge off, but not for long. As for aeration, the tank has two filters, one mounted on the side of the tank, and another submerged, so there is plenty of surface agitation. Added to that is a large airstone. The fish are not gasping at the surface, in fact they are mostly down lower in the tank, except the white clouds, who are mid to top of the tank. I'm looking into air conditioning the whole lounge area anyway, as in Cairns, it is bloody hot and humid. It's 9pm at the moment and I don't know what the humidity is, but it is very sticky and the temp inside is 30 degrees. So air con might be a goer anyway. At least that will help to regulate the tank during the day.

spedwards · 5th December 2006, 8:46 AM

My tank has been running at 28 - 30 for the last few weeks and hit a peak of 35 a month ago! It's back down to reasonable temps now after the cooler weather in Sydney over the weekend though.

I keep what people would say is a fish that is very particular about it's water conditions and have only had one fish lost in that time following the 35 day, but I suspect that there were other contributing factors that lead to that death.

As others have said, it's not so much the higher temps that cause the problem but the lower oxygen in the water. Just keep the air up to the tank and they should be fine!

4th December 2006, 4:01 PM	#1
digamma Member Join Date: Mar 2002 Location: Brisbane, Southside. Posts: 2,428	Fish tank overheating and killing fish I live in Cairns and now that we are in summer, the temps are climbing above 30 and at night, it ain't much cooler. The problem is that the fish tank is constantly above 27 degrees and is approaching 30. I drop in 2 feezer bricks morning and night to cool it down, but they only drop the temp 2 degrees. And by the time I come back, the temp is back up to where it was. What can I do? I'm not willing to spend the 100's of dollars that would be needed for a commercial setup, but would like to keep the tank at a comfortable level and stop the fish from dying. BTW, I have neons, black widows, white clouds and siamese flying foxes. To date I've lost 4 neons, 2 catfish and a flying fox. I'm not up for losing more stock. Apart from the temp, the water chem is fine and within limits for all the fish. __________________ The ultimate weakness of violence is that it is a descending spiral. Returning violence with violence only multiplies violence, adding deeper darkness to a night already devoid of stars.

4th December 2006, 4:11 PM	#2
Deckham Member Join Date: Jan 2005 Location: Essendon, Melbourne Posts: 6,967	Yeah, difficult situation. A few options. A commercial water cooler costs heaps, but will work. A portable airconditioner in the room could be cheap-ish and keep the room/tank cool. A floating 2ltr coke bottle with frozen water (overnight) will drop temps depending on your tank size. I used this method for a 'project' I was working on - worked well. __________________ Zenfolio

4th December 2006, 5:46 PM	#3
berek Member Join Date: Aug 2001 Location: 4305 Booshville Posts: 1,697	I've just purchased a chiller off ebay because I am in the same boat as you. Came home last week and the water temp was 31. Not good for a reef tank. It's a decent brand, Resun, which worked out to be quite cheap. 1/4 hp for $520 plus $30 shipping. LPS had them in stock for $795. They also had the 1/10 hp for $420 where the LPS was $595. Throw in a $60/$90 pump and should be good to go. Thought about room aircon but the running cost would be significantly more. __________________ Single item purchases over ::$400 to $1500:: and many other smaller trades too R.I.P. Minolta. 1928 - 2006

4th December 2006, 7:06 PM	#4
Agg Lord of the Pings Join Date: Jun 2001 Location: A Reported Post near you Posts: 25,469	I have similar fish (16 neons, for example) and I have been deliberately running my tank at 29C for the last 3 weeks (to kill off a suspected parasite/illness by breaking the breeding cycle). All the fish have been fine during that time and now we're back to 25-26C again. Are the fish doing anything else unusual, gasping at the surface etc? I vaguely recall something about warmer water needing more aeration.. __________________ www.overclockers.com.au - also now on twitter and facebook.

4th December 2006, 8:14 PM	#5
berek Member Join Date: Aug 2001 Location: 4305 Booshville Posts: 1,697	Thats another problem. The hotter the water the lower percentage of disolved oxygen. Significantly so. Plenty of online aquaria forums will have all the info you need. Just be aware the 1337 aquarists are just as bad as hardcore overclockers __________________ Single item purchases over ::$400 to $1500:: and many other smaller trades too R.I.P. Minolta. 1928 - 2006

4th December 2006, 8:17 PM	#6
Strange1 Member Join Date: Jun 2001 Location: Blaxland, NSW Posts: 2,655	Pump up the airstones! Warm water doesnt hold as much oxygen and the fish usually die from suffocation. Remove or open the lids on your tank, turn up the air pumps and get lots of surface gas exchange going. Apart from that just ice bricks if you need too. __________________ OCAU Extreme Cooling Club H2O Member AMD CPU 1400MHz @ 1672MHz / 2.13V / Ambient +20°C Cyclone 2 / Inline Rio1100 / Falcon aircon core

4th December 2006, 8:34 PM	#7
Agg Lord of the Pings Join Date: Jun 2001 Location: A Reported Post near you Posts: 25,469	Yup, aeration is no problem here (even with 50+ fish in a 4-foot tank) coz I have a 4 foot airwall and a small internal filter agitating the surface. But ice bricks etc don't really do much unless your tank is small. If you consistently get >30 temps you probably need a chiller. __________________ www.overclockers.com.au - also now on twitter and facebook.

4th December 2006, 9:28 PM	#8
Strange1 Member Join Date: Jun 2001 Location: Blaxland, NSW Posts: 2,655	I also remember reading that you can aim a fan at the surface of the water basically turning it into an evaporative cooler... __________________ OCAU Extreme Cooling Club H2O Member AMD CPU 1400MHz @ 1672MHz / 2.13V / Ambient +20°C Cyclone 2 / Inline Rio1100 / Falcon aircon core

4th December 2006, 10:06 PM	#9
digamma Member Join Date: Mar 2002 Location: Brisbane, Southside. Posts: 2,428	Thanks for the replies so far. Like I said, a commercial chiller is out of the question. I couldn't justify spending that on the fish setup, and the missus would have a hissy fit. And I wouldn't blame her. On the other hand, if I had the moeny, I'd probably do it though. Still, can't afford it. I'll see if i can find freezer space for a coke bottle or 2. At the moment I'm using esky freezer bricks and they are taking the edge off, but not for long. As for aeration, the tank has two filters, one mounted on the side of the tank, and another submerged, so there is plenty of surface agitation. Added to that is a large airstone. The fish are not gasping at the surface, in fact they are mostly down lower in the tank, except the white clouds, who are mid to top of the tank. I'm looking into air conditioning the whole lounge area anyway, as in Cairns, it is bloody hot and humid. It's 9pm at the moment and I don't know what the humidity is, but it is very sticky and the temp inside is 30 degrees. So air con might be a goer anyway. At least that will help to regulate the tank during the day. __________________ The ultimate weakness of violence is that it is a descending spiral. Returning violence with violence only multiplies violence, adding deeper darkness to a night already devoid of stars.

5th December 2006, 8:46 AM	#10
spedwards Member Join Date: Aug 2003 Location: Sydney Posts: 850	My tank has been running at 28 - 30 for the last few weeks and hit a peak of 35 a month ago! It's back down to reasonable temps now after the cooler weather in Sydney over the weekend though. I keep what people would say is a fish that is very particular about it's water conditions and have only had one fish lost in that time following the 35 day, but I suspect that there were other contributing factors that lead to that death. As others have said, it's not so much the higher temps that cause the problem but the lower oxygen in the water. Just keep the air up to the tank and they should be fine! __________________ My pics @Photobucket