Goldfish

[Flubberlump]

Hi all. I'm not new to the site, but I have next to no knowledge on the subject of cold water fish as I keep tropicals - apart from the usual fishy care. I hope that this thread is therefore in an appropriate place.

I'm looking for advice on behalf of my sister. She has a 120ltr cold water tank with one comet goldfish and 1 butterfly loach. The usual story whereby a store sold tiny goldfish with a 40ltr tank applies. She had another comet but he died a few months ago due to a tumour he had (we assume). The fish are about 6 years old, she has upgraded the tank 3 times since she got them. The current tank is her limit due to space etc.

The comet is about 12cm long. The tank is mature with a large canister filter and a HOB. Temperature varies between 22-25C throughout the year.

She would like more fish, but I have no idea whether this is possible due to tank size and fish compatibility etc. She knows (now) that she is very limited. From what I've read comets can outcompete other fish for food, certainly slower moving ones. More goldfish are obviously out of the question but are there perhaps smaller fish that could be added? Probably temperate fish due to the tank temps?

Thanks in advance.

 

[juhason]

Comet Goldfish get very, very large... up to a foot or more. A 30 gallon tank is not enough for even one comet unfortunately so I'm not sure if adding more fish would be ok. Maybe while he is smaller it should be fine, however eventually the goldfish's bioload will be too large to support more fish (and even to support just him) OR he'll eat them OR everyone's growth will be stunted (due to increase in dissolved toxins)
 
Giant Danios, Rosy Barbs, Buenos Aires Tetras, and Black Skirt Tetras are good schooling fish that can probably compete with goldfish and are too big to be eaten by it (at his current size) who enjoy and even thrive in lower temperatures.
 
Just be sure to research the fish before deciding to put them together! And just know that they cannot be permanent buddies. Eventually the goldfish will have to go (to a bigger tank or someone who has a bigger tank)

 

[Flubberlump]

Thanks for your reply. Yes I realise that he will outgrow the tank. My parents have a pond but they're wary about putting fish in it as they have cats. Currently it's a wildlife pond. How long will it take for him to reach full size? He's around 6 years old currently.

Thanks for the fish suggestions. Would they be ok with the butterfly loach also? I'll have a word with her. Sadly she's quite attached to him and it'll take a lot of persuasion for her to give him up. Unfortunately it's the classic baby goldfish purchase problem. It does make me cross that it's so easy for people to buy fish that are totally unsuitable for their tank, without proper advice.

Thanks again

 

[Efishent]

Well, your goldfish may never reach full size, as its growth will probably be stunted in this tank. If this is the best you can do for the goldfish, I suggest that you keep the tank as it is without adding anything else, and let the goldfish get as big as it can get. I have a cat who loves staring at my goldfish, but cats can be total chickens; I doubt they would actually get themselves wet in pursuit of this goldfish if it were in the pond. I think that it could be a great idea to put the goldfish in the pond, if it weren't alone.

Edit: these fish look compatible, I think that they are fine if the loach and the goldfish stay at similar sizes.

 

[Jeremy180]

I too would be leery about putting the goldfish in a natural pond, I don't know what predators you have over there, but here in the US, we have ospreys, herons, Racoons, foxes, owls, Possums Bobcats, ETC. in addition to the odd cat.
If the current tank really is her limit, I would consider getting a separate tank for the loach, and maintaining goldfish's tank with at least twice weekly 70% water changes.
This is far from Ideal, as goldfish really need at least 260 litres(68 gallons) per fish and a tank with a minimum of 45 centimeters(18 inches) at the smallest (usually front-to-back) dimension but if that's really the best she can do...

 

[Flubberlump]

Thank you both for replying. I haven't spoken to my sister properly about it yet, but in general conversation she's just mentioned that she would like a new tank as her hood and stand are looking a bit tatty. I've offered to assist in finding a new tank Hopefully sooner rather than later. I'll do my best to steer her towards a bigger tank but cost and space constraints will play a part too. She knows that he needs a bigger tank though, she maintains it properly and he is well looked after apart from the tank size. She does her best for him, like I said she's upgraded the tank 3 times in the time that she's had him.

Jeremy we have a heron in the area but I think the chances of it getting anywhere near to landing in their garden are slim. They do have cats though. I'm not sure how my parents would feel about having him in the pond because of the cats. I'll mention it to them though. It's not a huge pond but much much bigger than his current tank. If he did move into there then they'd definitely get him some company.

 

[juhason]

I still think she is better than most, so no sweat! Most people buy the adorable tiny goldfish and keep them in betta bowls (which are meant for no fish whatsoever). I commend her for taking such good care of a 10 cent fish (or however much it is where you are) whereas most would've just let it die cause it didn't make a dent in their pocket. 

 

[Flubberlump]

No she really loves him! She'd just like him to have some company. Unfortunately no more goldfish can go in that tank. He started off in a little 40litre and as he grew he moved to a 60, 90 and then 120 litre I believe.

Thanks for your comments