can a heater be too big?

Discussion in 'General Discussion' started by rainbows, Mar 23, 2010.

  1. rainbowsValued MemberMember

    I just purchased a marineland stealth 200w for my 29 gallon. The 200w is for up to 55gal. Should I have purchased the 150w which is up to 30 gal? The reason I ask is because I've put the 200w in the tank and it's set for 82, however, the temp in the water is only 77... I went to bed with it set at 77 and woke with the tank at 72. Do most heaters have a 5 degree difference like this?

    **by the way, the reason i went with the 200w is because this part of the house can get cold during the night and thought the 150w would be working too hard... not sure if this was good reasoning:-\
  2. ButterflyModeratorModerator Member

    The 200w is fine. Regardless what size the heater it should only heat up to the temp it'set for. Try measuring the temp with two different thermometers. There shouldn't be that large of a difference over night.

  3. _Fried_Bettas_Well Known MemberMember

    Difference in 150 and 200 isn't that much. A larger difference might be bad because it would change the temp too fast. The numbers on the heater don't mean much, you need to adjust by trial and error until it is coming on at the temperature you want it to. I think the new stealth heaters have a light that come on when it is working, I really dislike the older one I have in one of my tanks because you can't tell when it is working or not. From what you've said so far I'd wonder if it is working at all. Turn it up and put your hand on it (if it doesn't have a light), you should be able to feel the heat if it is working. Do this in the water because it is designed to shut off when not in the water.

  4. rainbowsValued MemberMember

    thanks you guys. I have 2 different thermometers in the tank (at different ends) and they both have the same reading (within 1 degree).

    This is the new one so the light is at the top and when the light goes red I feel heat coming from it. Just seems like there shouldn't be a 5 degree difference...
  5. mosin360Well Known MemberMember

    I got a 300w in a 38g with no issues.
  6. LyndaBFishlore LegendMember

    I have a Marineland Stealth 250W Pro-Heater in my 46 gallon tank and absolutely love it. It has the green light when "working" and red light when not. Plus, and this is a huge plus to me personally, it's really easy to set a temperature. There's really no guessing with this model. :party0024:
  7. JayseeFishlore LegendMember

  8. cm11599psWell Known MemberMember

    I'm not sure what size heaters are good for what size tanks, but you need to be sure you have the correct size heater for your tank.

    1) Having too small of a heater will lead to the heater being on way too much because it can't handle heating all that water. This is especially true in a cooler house.

    2) Having too big of a heater is not good either. I believe in this case the heater goes on but shuts off very quickly which is not good either.
  9. AquaristFishlore LegendMember

    Good afternoon.

    I have the Stealth Pros with the Red/Green indicator lights too. Love 'em! I have 3 in my 265g and they are accurate within 1 degree. I agree 5 degrees off is a bit much. I'd give it another 24 hours and see where your temperature is then. You may need to return it if it doesn't improve.

    Try placing your heater horizontally several inches above your substrate and directly under your filter out flow if possible. This will help to give the tank a more even temperature.

  10. lanlesneeWell Known MemberMember

    I'm willing to go out on a limb and say your heater is really set for 72 degrees. I think the tank was 77 degrees because the room temp was around that, so the heater wasn't even on until the room cooled down enough for it to come on at 72.
  11. leeishomValued MemberMember

    I use 3 different therms.

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