The water temple is very easy to beat in MQ. There is like nothing really challenging in it. And that's just one thing. I personally found the part you have to break the barriers (in the castle) the most challenging out of the whole game. Not saying it was hard but more saying like how easy the...
I didn't find it hard at all. Both the original and the 3DS version are easy in my book. Everything is mirrored and yes some puzzles are a bit tricky but personally I find it even more easy than the normal version.