I missed this comment I am sorry!! Yes it is a tank direction. I thought I was being smart by saving time and plastic by printing it hollow, but it FLOATS lol, so I have to fishing line tie it to a rock somewhere. I’ve now replaced my single 1” PVC return with 4 different 3/4” LocLine with RFG nozzles. Gonna end up getting addicted to this 3D printing, wife will keep finding more and more stashed away in corners, slowly printing whatever I can find on the internet….