Us gallons works best for me, what I really like to know is tank dimensions. A good example is 20 gallon high and a 20 long. What works in one many times won't work in another.
I voted US gallons. Strangely enough, everything in Canada is metric, except for fish tanks for some reason. They just aren't stated in litres. I tend to use dimensions when not on the forum, and I can convert litres to gallons if I have to.
Got to be litres. The whole world (except America and a few small countries as far as I know) uses litres. Although Britain uses metric systems now we are not truely metric. Lots of our goods have simly had their measurements transfered to mm from inches. For instance timber is available in 19mm thicknesses which is near enough 3/4 inch. If we were truely metric it would have been 20mm. Copper pipe is sold in 22mm diameters. This is near enough 7/8 inch. It should be 20mm or 25mm. Things are changing but not as quickly as some might think.
Anyway, time to go. I'm off down the pub for a nice 568.2612ml of beer!
I go with us gallons, I got used to using us gallons for measuring liquid so it's easier for me.
There were those times when I ran into litres and fishtanks, that was quite confusing and I constantly had to go to online calculators and converters.
I've been reading through and noticed that most people (myself included) have voted for what's easiest for them. However, as Waterloo Kid rightly pointed out, most of the world uses metric measurments and, as there is a worldwide move towards metric (even if some places are slower than others!), it makes sense to me that we use litres.
But it looks like US gallons will have it - mainly becuase most of the people here are from the US!
Well, I grew up in Sweden (metric) and have spent most of my adult life in England (still mainly imperial IME), but I have to admit the 2.5 cm/3.78 litres rule just doesn't have the same ring to it....
I'd be quite happy to go with US gallons as a specialized fishkeeping measurement.
I personally prefer UK gallons and i base my stocking on UK gallons as i live in England and i think the fish appreiciate that extra little bit of space when it comes to stocking