What is the smallest body of water I can fish from?

As I jet about Terraria, trying to fish, I find that some bodies of water don't seem to be large enough to fish from.

Whether they are too shallow or just too small I do not know; so therein lies the question:

What are the dimensions required of a body of liquid in Terraria to make it fish-able?

3 Answers

You need 75 tiles of OPEN water. Note that any water that touches the ceiling and all vertically beneath it is not counted - I tested with the fisherman's pocket guide. But note that you will have a penalty on your fishing power which reduces until the water is 300 tiles in total.

Note that the requirement does not calculate the exact amount of tiles filled with water - having 50 tiles wide of 1.5 tiles of water can be a valid fishing area.

On earlier phases where larger water bodies might not spawn near you base you can drain nearby pools of water to a open area under your base as an early game fishing area. Which you can later lower by digging it's base to make it a cavern/underground fishing area.

I believe from what I've picked up, that the minimum number of 'blocks' of water needed to fish is about 70 (total number of 'blocks': e.g. a 7 by 10 block lake; this is about the smallest I've been able to catch anything in), with 300+ being optimal (i.e. no penalties). To be taken with a grain of salt as this is mostly derived from anecdotal evidence.

5

To not fish junk, you'll want a lake with at least 300 blocks of water. I usually achieve this by digging a 10x30 hole and using the water duping bug to fill it.