Linwood
Aquarium Advice FINatic
I'm confused by heater sizing. I've got a 45G tank and a 100W heater and all is good, but frankly have no idea if it's running 95% of the time or 2%. Overkill is easy and cheap in that size.
I'm getting a 220G tall tank (72x24x30). I started looking at advice, and most advice seems volume related (e.g. I've heard 5 W per gallon = 1100W). While proportional to volume at initial fill, heat loss is proportional to the surface area not volume for loss into the room, so any guidance that is proportional to gallon-age seems wrong to me.
So I found this nice calculator:
Aquarium Heater Calculator
That says with even a whopping 15 degree difference I need 80W to break even; hugely different from 1100W (and at the more appropriate 5 degree difference break even is 26W).
When I look at Hydro (I liked their canister heater look at least) they don't quote anything larger than 80G and suggest 300W.
I've read several threads recommending as many as three 1000W heaters in similar size tanks.
I looked at Cobalt's sizing guide, and plotted gallons against wattage, and it is nearly completely linear, which just doesn't make sense with the square vs cube relationship of heat loss. Unless they are assuming people dump cold water in at water changes and it needs to heat fast? (Do people really do that?)
So what am I missing here? Do I really need a big honking heater for a (non-sump) 220G tank? Or is something like the Hydor ETH 300 (300w) much more than enough?
I'm getting a 220G tall tank (72x24x30). I started looking at advice, and most advice seems volume related (e.g. I've heard 5 W per gallon = 1100W). While proportional to volume at initial fill, heat loss is proportional to the surface area not volume for loss into the room, so any guidance that is proportional to gallon-age seems wrong to me.
So I found this nice calculator:
Aquarium Heater Calculator
That says with even a whopping 15 degree difference I need 80W to break even; hugely different from 1100W (and at the more appropriate 5 degree difference break even is 26W).
When I look at Hydro (I liked their canister heater look at least) they don't quote anything larger than 80G and suggest 300W.
I've read several threads recommending as many as three 1000W heaters in similar size tanks.
I looked at Cobalt's sizing guide, and plotted gallons against wattage, and it is nearly completely linear, which just doesn't make sense with the square vs cube relationship of heat loss. Unless they are assuming people dump cold water in at water changes and it needs to heat fast? (Do people really do that?)
So what am I missing here? Do I really need a big honking heater for a (non-sump) 220G tank? Or is something like the Hydor ETH 300 (300w) much more than enough?