Fluxuating water temperature

[linyoest]

I need some suggestions on maintaining the water temperature in my 55 gal aquarium. I set it up about 3 months ago, so it's pretty new. My home does not have AC, and the weather here has been in the 90's. This is causing the water temperature in my tank to fluxuate--my set temperature is 78, but these hot days it goes up as high as 84/86 degrees! But will cool off during the night. I keep the light off during the day and keep a fan blowing on the aquarium, but this doesn't keep the temperature down enough, and I am concerned about the stress this is causing my fish. In fact, today I discovered one of my mollies has Ich, so I am now treating for that.

Any ideas on how to keep the temperature from fluxuating so drastically? Should I use my heater to increase my set temperature to 84, or would that just cause the tank temperature to go up even more on these hot days?

As an FYI, I have 7 adult mollies (and a lot of little mollies ranging from 5 weeks to 1 week old) along with 7 cory cats, two algea eaters and two yoyo loaches. I started my tank with 8 mollies (one died last week :sad: ); they have been having babies like crazy--fortunately my LFS will take the jr fry, so my tank won't get overcrowded.

Well thanks in advancec for any suggestions.

Linda

 

[Kasakato]

If the changes are slow is should be ok. In my tank I go from 78 to 87 everyday. I found out that 87 is the lowest I could keep the tank with out a chiller. So I just let that go. No problem, no fuss, no muss. But take a look at this: http://www.aquariacentral.com/forums/showthread.php?t=52858 It will give you some tips on how to lower the temp if it gets to high.

Your fish maybe dieing because your tank is cycling. Do you have a test kit? How often are you doing water changes?

 

[Aqualung]

My tanks are set between 76 and 78, and on really hot days they creep up to 84 or so. If they get any warmer I just do a cool water change, dropping the temp down gradually (one degree or two at a time).

 

[linyoest]

Aqualung and Kasakato:

Thank you so much for your feedback. I am thinking that my fish are tolerating the temp changes pretty well so far, but just wanting to make sure. When it's hot my tank also goes from 78 to about 86 every day, so it sounds like this might not be something to panic about. I will check out that link; and thanks for the tip on adding cooler water.

I do have a test kit, and I am testing the water every three or four days and doing water changes once a week. Something I read on this site makes me think I should be doing water changes more often right now. My tank probably is still cycling, and even if not my mollies are having babies so fast I can't count the fry anymore--just had about 30 more last night! I am probably going to set up a nursery tank so I can get as many of the littlest ones out of the big tank as possible.

Thanks again for your suggestions.