water temp and heater issues--advice pls?

stephanieleah

Yesterday I added two new dwarf puffers to a ten gallon tank yesterday that has been set at 78 degrees. I hadn't noticed this before, but I think my lights are heating my water. When the lights are on, the heat is about 83 degrees. When the lights are off, the temp drops to about 78 which is what the heater is set for. I have two thermometers and they both say different things.

What should I do?

The only things I can think of to do are:

1. Put the DP's in my 29 gallon community while I fiddle with the heater and lights and work out a way to make it all stable (don't know how they'll do with the other fish, they are friendly with each other anyway)

2. Keep the lights off and buy a new hood that is further away from the tank so it doesn't heat the water (I don't even know for sure if that's what's going on, I'm just guessing it's the lights that making the water so darn hot) (translation...spend even more money)

3. Set the heater to 84 degrees and let it remain there, and risk that the lights will raise the temp yet even higher.



The don't seem to mind, but time will tell. I don't know them well enough to see "stress" in them.

WisFish

What type of bulb do you have in there? An incandescent? Will a compact fluorescent fit in the hood?

stephanieleah

Oops thanks I forgot to mention that--I currently have two compact flourescents in there (only 10W each) and it does feel quite warm up there. Lower wattage bulbs are on my to-do list for that hood but until then...not sure.

jaysee

In the wild, the temperature fluctuates like that every day and night. I wouldn't worry and would leave things the way they are.

Angel079

I doubt its your lights giving off that much heat to heat the water that much; if its the lights I have in mind you buying for this 10g anyway.
I'd also not worry about the fluctuation as its only natural.
But check if your heater vent blows right on to the tank that may cause this.

stephanieleah

okay, i figured it out but didn't post a follow up because there weren't that many responses.

i went to yoga yesterday for two hours and when I came back it was four degrees hotter than when i had left. so i went and bought a new heater and since i put it in last night the heat hasn't fluctuated a whole degree since. the DP's aren't minding all the craziness, though. They've settled in so comfortably that they've stopped huddling around together and have officially claimed their hierarchy rights. Glad I have so many hiding spots for the less dominant.

and I'm super glad the extreme flux in temp hasn't killed any of them. hardy little suckers.

and yes you're right Angel it wasn't the lights (i was grasping there)

Tyyrlym

Never trust the dial on the heater. It's in no way calibrated and is at best a wild guess. Always rely on a thermometer. In my opinion the best kind are the simple 3 dollar old school "mercury" style that attach on the inside with a suction cup. They're far more reliable than the stick on the outside LCD ones and not as flakey as a digital. Adjust your heater up and down based off the thermometer's reading. I think my heaters are set at like 81 or something to keep my tank at 78. If you're worried about the lights then its easy to go to the home improvement store and buy a piece of 1"x2". Cut it into short lengths and use it to raise the light either another inch or two inches off the surface of the water.

stephanieleah

thanks for the reply...i actually figured out that it was the heater. i bought another one like i have in my larger tank (same wattage and same brand different model) and the heat has stayed within a degree. i think it was just heating too fast, the temp would spike, then it would cool way down before clicking on again. didn't lose any fish in the process so that was a plus.

Tyyrlym

A ten gallon tank won't be as stable as another tank. It's got a significantly higher surface/volume ratio than large tanks and therefore heats and cools much more rapidly. Not saying the heater couldn't have been defective, but heating a small tank is a far more strenuous task and some brands might not handle it as smoothly as others might.