My first question...what are you going to grow in these beds, how tall does it grow and how are the plants on the bottom levels going to get light? If you are talking about 3 or four levels and a 10 gal aqu. underneath, the plants will have to be very short and a good light source for them. Yea, I know...I didn't answer your question about the fittings....I'm sure Badflash or Jeff can handle that answer...me....I'm just the nay-sayer here