aluminum in ponds

Question
I have built a large pond with a waterfall.  I realize now that the shelves along the perimeter of the pond are not big enough.  Can I safely use pieces of aluminum to reach across one end of the pond to set plants on? I am a bit worried if aluminum could be toxic to plants or goldfish.
Thank you for your help with this.
Bonnie Jones

Answer
Hi Bonnie,
Thanx for your question.  Aluminum is definitely toxic to fish.  Check this out http://www.cnr.vt.edu/extension/fiw/fisheries/pondslakes/interpreting_pond_water...

I would recommend using rock.  Many places that sell rocks sell thin slabs of rock that you can use as you were going to use the aluminum.  Look for merchants who specialize in selling decorative rock.  I hope this helps.
Tom