It's certainly possible, and their requirements are identical to that of koi. While juveniles might be okay in a 110-litre system for a while, once they're above 10-12 cm, they really would need to be moved outside. A heavy-duty external canister filter would be practically essential given how messy these fish are.
One caution I will make is that wild-caught carp might need deworming. On the last occasion I tried to keep a group of very small wild-caught crucian carp, I found that no matter how much I fed them, they lost weight and eventually all three died. If you have access to farmed carp produced for ponds, so much the better. The larger garden centres periodically get things like mirror carp and ghost carp. Tench are also widely traded in the UK, and these are extremely hardy fish.
If you simply want some interesting coldwater fish, then I'd put carp to one side and look at other species instead. If you visit a store like Wildwoods in Enfield that specialises in coldwater fish, you'll find a variety of things like bitterling, sunfish, minnows, darters, gobies, loaches and other North American and Chinese fish ideally suited to indoor unheated aquaria. A surprising number of "tropical" fish actually do better in unheated, room-temperature aquaria as well, perhaps most famously the bearded corydoras
Scleromystax barbatus.
Cheers, Neale
just want to know if this would be possible and what would i need?
