Concrete Pot in Koi Pond?

[Sisha]

Hello, I am admittedly a Newbie to Koi Ponds. I recently bought a Japanese Iris to beautify the margin of my pond. It needs to be partially submerged, and the plastic pot its in is not aesthetically appealing, since it is visible. I am looking into stone pots that are made of Cement, Perlite & Moss. Do you think any of these elements would be harmful to the fish? Thanks

I wouldn't worry to much about concrete pots. I have a few concrete items in my 12000lt pond including, a solid tall block/plinth to support a concrete lotus water feature, a frog, various besser/cinder blocks to support plants and the ph is very stable. However, I recently took out a water lily that was in a plastic pot and the plastic had peeled badly. Never again will I use plastic if it's not black. I can imagine how my fish have all tried ingesting small pieces of plastic.