I hoped a lot of water would ease the problems with high nutrients, but I had a few deaths among the fishes and feeding the to much. So now the algae has taken over. I changed half of the water in the aquarium, which reduced the N and P somewhat, but the rocks are still covered by red slimy algae. The next step will be to add a filter with phospate remover like Rowaphos. I´m still trying to work out how to build a nitrate reducing filter. Meanwhile I have added a small army of snails. Now I have chitons, limpets, flat periwinkles, edible periwinkles, topsnails and a few blue rayed limpets.
Here´s a photo of the front glass. A week after I introduced the snails the glass was cleaned.