Most typically have intake on one side and outflow on the opposite but that's not a requirement as long as you have adequate flow. Pipe placement is really up to you and the needs of the tank. Appears that you have a decent ripple across the water surface, so there's enough movement for gaseous exchange. Are there any dead spots where things settle more than in other areas of the tank?How does this look? I got lily pipes. Should it be higher or lower? Is intake and co2 look like okay spots?