Do I *need* A Heater For Goldfish Growth?

I'm about to start cycling a 75 gallon aquarium for my common goldfish. He's grown about an inch and a half-ish since I got him 2 months ago (he started about 1.5 inches, now he's about 2.5-3 inches), currently in an unheated 29 gallon tank. I've read conflicting information regarding goldfish growth and temperatures, so I'm just curious:

1. Do they NEED warmer temperatures to grow after a certain point, or do the warmer temperatures just help with growth? The tank is currently sitting at room temperature, which fluctuates anywhere from 69-72 degrees.

2. If I get a heater, what temperature should I raise the tank to?

3. How many watts should I use in a 75 gallon tank? I'd like to use 2 heaters instead of 1.

 

Nope, common goldfish do not require heaters to grow past a certain point. You're good on that front.
On another, there is a good chance that yours might outgrow the tank, just wanted to let you know.
But that temperature is definitely good year round for goldfish. Commons can go down as low as 40 and be fine. Actually, water warmer than 75 degrees is detrimental to goldfish health

 

Thank you! Also, I forgot to mention in the initial post, I'm planning on building a pond in the next year or so, so he'll be going into that when it's done.

 

I agree with Rtessy, except the part about 75 F being too warm. My tank usually fluctuates between 78-80 F. Also, many goldfish are farmed in tropical climates and then imported into the US. I think for many people, saying that it needs to be below 75 is asking too much and would require a chiller.

 

Nope, common goldfish do not require heaters to grow past a certain point. You're good on that front.
On another, there is a good chance that yours might outgrow the tank, just wanted to let you know.
But that temperature is definitely good year round for goldfish. Commons can go down as low as 40 and be fine. Actually, water warmer than 75 degrees is detrimental to goldfish health

Goldfish can certainly thrive in temperatures warmer than 75 degrees. It’s a myth that they are “cold water” fish. Thailand, for example, produces some of the finest quality goldfish in the world although their temperatures are warm nearly all year long. Goldfish are adaptable little things.

As for the 75 gallon, you CAN use a heater if you want—warmer water will speed up the initial growth process a bit. But frankly it is totally unnecessary, probably better to spend that money somewhere else.

 

Thank you! Also, I forgot to mention in the initial post, I'm planning on building a pond in the next year or so, so he'll be going into that when it's done.

Oh that's wonderful! Honestly, a 75 alone is amazing!
And thanks everyone else, sorry, you know how the internet is with information

 

I agree with Rtessy, except the part about 75 F being too warm. My tank usually fluctuates between 78-80 F. Also, many goldfish are farmed in tropical climates and then imported into the US. I think for many people, saying that it needs to be below 75 is asking too much and would require a chiller.

That's good news at least for when I eventually move him outside. I live in FL and it gets HOT here, lol.

Goldfish can certainly thrive in temperatures warmer than 75 degrees. It’s a myth that they are “cold water” fish. Thailand, for example, produces some of the finest quality goldfish in the world although their temperatures are warm nearly all year long. Goldfish are adaptable little things.

As for the 75 gallon, you CAN use a heater if you want—warmer water will speed up the initial growth process a bit. But frankly it is totally unnecessary, probably better to spend that money somewhere else.

That is EXCELLENT to hear. One of the reasons I was so excited to keep this guy is that I wouldn't have to buy a heater, lol.

Oh that's wonderful! Honestly, a 75 alone is amazing!
And thanks everyone else, sorry, you know how the internet is with information

No need to say sorry! I think we're all constantly learning. And thanks, I'm trying to do the best I can for him until I get a pond!