Temperature fluctuations

[bosk1]

Hi all. Most of the regulars here know my tank is relatively new--set it up for cycle in November; have had fish since early December. Although I did a lot of research on certain things, there were certain equipment areas I didn't look into very deeply, such as heaters. As a result, I bought an aquarium kit instead of buying things separately. So I've got a fairly cheap glass heater. Off the top of my head, I can't remember how many watts, but I will look it up and post it when I get home if people want to know.

Anyhow, my question concerns temperature fluctuations. The temp. seems to fluctuate almost 4 degrees at times, which seems like a bit much. I don't think I would normally be overly concerned, but I am heat treating for ich at the moment, so I do not want the temp to drop below 87. It seems to mostly stay around 88-89, but has dropped to 86 at times, and gone as high as 90-91 at times. Both are a bit alarming. I really do not want to go out and buy more equipment at this point unless necessary (although I will likely upgrade somewhere down the road). Does it seem like I have a really crappy heater, or is that much fluctuation pretty normal?

[jcarlilesiu]

typically many of the cheaper heaters thermostats are VERY inaccurate. My old one didn't even say a temp, just had a knob on it that i knew should be "about right". At one point my tank was nearly boiling (exageration) even though i never touched the heater. I think its just the nature of the beast, not much you can do. I would upgrade as soon as possible.

I just bought the kind that are totally submursed 200W and either my thermometer is broke or it doesn't fluctuate at all.

[Jchillin]

I would suggest an upgrade to the Visi-therm heaters Reviewed Here Dependable to a fault.

[crazycat]

fwiw my temperature fluctuates between 77-81 degrees. i assume that this happens over enough time to not shick the fishes. no one ever seems to be upset, so i figure it's ok.