Coldwater tank capacity

[Peacelily]

I've seen it suggested that a coldwater tank can accommodate fewer fish per gallon than a tropical tank, and I'm trying to figure this out. I thought oxygen was the major consideration, but cold water holds more oxygen than warmer water, and fish use oxygen at a slower rate in cold water due to reduced metabolic activity. Waste production certainly shouldn't be higher at a lower temperature. Are there other factors to consider?

I know that goldfish are "dirtier" than tropical fish, but I have white clouds and dojo loaches. Due to their size, the loaches need a lot of space just to move around, and I'm hoping I can fill a larger tank with more shoaling fishes than the "0.5 inches of fish per gallon" I've seen recommended.

Any thoughts?

 

[Cichlid Kid]

If your sub-tropical tank does not include goldfish then imo you could stock to a normal tropical fish standard using wcm minnows and dojo loaches.

 

[Peacelily]

That's reassuring, thanks.