You're in a no win situation regarding leaf drop, Midus - evergreens lose leaves too, just not all at once, a few at a time all year. Personally, I'd go for the Acer, at least you know when the leaves will be falling and can take evasive action to stop them getting in the pond.

i agree and connifers are poisonas to . willow is also but i wouldnt plant that anyway lol .

go for the acers Midus, total Zen with the water & as they are small netting the leaves out once a year will be fun. Do avoid the evergreens regards water quality.

I have conifers near my various water features, and they're entirely in keeping with the style of planting. Hinoki cypress (Chamaecyparis obtusa 'Nana Gracilis') and some of the junipers are very architectural. Not poisonous and in fact their leaves will do far less damge in the water than many others, even native, which have higher tannin levels. Hve a look at some of them for style. Conifers have it aplenty. Phil J