Loaches Online Forum

i know this is a silly question but iv seen a few freshwater tropical fish tanks with fancy goldfish in can cold fish and tropicals live together ok ?????????

I don't recommend this because fish are cold blooded, which means that water temperature affects rate of metabolism and wrong metabolism rates can cause health problems. The second problem is that goldfish will eat the average community freshwater fish.

Many fish can survive in a wide range of temperatures, and remember that some "tropical" fish are actually "cool water". As an example (of an incompatible fish), the water temperature that Danio margaritatus and Yunnanilus sp. 'rosy' live in in the wild varies between 16 and 30 C (that's around 61-86 F) throughout the year, with 20-22 C being the ideal temperature for best colour in the danios.

Yes, Goldfish are big eaters and are coldwater so not a good idea to mix with tropicals. Maybe with a DOJO loach

thanks guys i wasent planing on putting them all togeather i was just intresterd in if you could or not becouse i had never seen tropical and freshwater together in all the time iv keep fish lol witch is for a long time thanks anyways guys

ClownLoachSharky wrote:Yes, Goldfish are big eaters and are coldwater so not a good idea to mix with tropicals. Maybe with a DOJO loach

Well, they can be mixed at the right temperatures, at the points where the ranges for both species overlap and with species which grow large (probably with any that reaches 10 cm or more), but that is not ideal for the either fish most often. Fancy goldfish, which do best in higher temperatures compared to common goldfish, are not too difficult to mix with "tropicals".

There are a few Corys, such as Corydoras paleatus, C. zygatus, Scleromystax barbatus and S. macropterus, which can be mixed with fancy goldfish without any problems, and 3 out of those are "tropical" species. Plecos, loaches and danios are some of the groups where it is possible to find fish that are "cool water" and "tropical" at the same time.

Also, published work showed that goldfish can survive at any temperature between 0 and 41 C. And another paper used that range to demonstrate that 17-27 C is the only "safe" range for goldfish because at 0-17 C and 27-41 C, a goldfish has the potential to die if not acclimatised very slowly to the temperature… but of course, on its own, that doesn't mean anything because how often would someone be moving a goldfish from one extreme temperature to another? Just thought you'd appreciate the irony in that

Basically, the problem is that fish are classed into "cold water", "cool water" and "tropical" instead of "these are the ranges this species does best at".

KittyKat wrote:

ClownLoachSharky wrote:Yes, Goldfish are big eaters and are coldwater so not a good idea to mix with tropicals. Maybe with a DOJO loach

Well, they can be mixed at the right temperatures, at the points where the ranges for both species overlap and with species which grow large (probably with any that reaches 10 cm or more), but that is not ideal for the either fish most often. Fancy goldfish, which do best in higher temperatures compared to common goldfish, are not too difficult to mix with "tropicals".

There are a few Corys, such as Corydoras paleatus, C. zygatus, Scleromystax barbatus and S. macropterus, which can be mixed with fancy goldfish without any problems, and 3 out of those are "tropical" species. Plecos, loaches and danios are some of the groups where it is possible to find fish that are "cool water" and "tropical" at the same time.

Also, published work showed that goldfish can survive at any temperature between 0 and 41 C. And another paper used that range to demonstrate that 17-27 C is the only "safe" range for goldfish because at 0-17 C and 27-41 C, a goldfish has the potential to die if not acclimatised very slowly to the temperature… but of course, on its own, that doesn't mean anything because how often would someone be moving a goldfish from one extreme temperature to another? Just thought you'd appreciate the irony in that

Basically, the problem is that fish are classed into "cold water", "cool water" and "tropical" instead of "these are the ranges this species does best at".

verry intresting kat you deffo got me thinking now lol i wasent goin to mix my fancy fish and tropical togeather but i must admit i did have a little think once lol just amazed me when i seen a few fancy fish in a tank with freshwater tropicals

Well, either those people are mixing cool water fish with cool water fish (which isn't any different to mixing coldwater fish with coldwater fish or tropical fish with tropical fish), or they're harming the tropical or cool water fish by not giving them the right conditions: the latter just demonstrates that someone doesn't know about the fish that they're keeping and is, unfortunately, the more common of the two.

true i told them that there not meant to be together one is tropical and one is coldwater thay said thay have had them together for agers so i duno leave em too it nothing i can do just thought i would see if anyone els has done it before becouse iv never seen it like that before

Can you remember which species they had?

The temperature will affect the life span and susceptibility to diseases, but the amount by which it does will vary quite a lot between different species

KittyKat wrote:Can you remember which species they had?

The temperature will affect the life span and susceptibility to diseases, but the amount by which it does will vary quite a lot between different species

think thay had a blue powder dewrf garumie like mine and two fancy wish one was a red cap arounder and one was some sort of lion head but didnt have the bubbles around its head but the shape of its body was the same as a lion head