I realise I probably should have posted in this section. With time on my hands I am attempting to build a raised pond to house turtles. After very rushed calculations I ordered 70 concrete blocks and 5 bags of cement. I already have a ton bag of sand. The plan was a raised pond three blocks high, 5 x 4 blocks, rendered with concrete finish sealed with pond seal. Would you recommend a 3:1 mortar mix as I have read in a previous post. Would this also be a suitable mix for rendering the blocks inside? I am slightly worried that we will run out of cement and wondered if I should buy more whilst I can. Do I need to reinforce the base with steel rods. could I improvise with old bicycle frames cut up? I am trying to use resources available as I would prefer not to have to burden the local driver with more work. I have access to drive gravel and a small hand compacter or punner as my dad used to call it. Any expert advice would be most welcome. xx