Thanks for the reply

The cinder blocks are there to stop the rocks from falling into the deep end. Probably not a bad idea to make a line of plants there. There's geoteck in the shallow to help hold the rocks up when we put them in so they don't just sink into the clay. I'll be putting in an aerator in that shallow end and maybe tilting it to push the water towards the tip of the shallow where the biofilter is.

We do not want algae and there's lots around this area, so planning to mitigate that. Hopefully with enough water movement.

Cheers