I don't know much about it, i just buy/cut/build, ... but ...the trough is a luxury if you can organise it. There is no grow media (no gravel)... there are plants that are inserted in to styrofoam, styrofoam floats and shields the water from the the sun. The plant roots just dangle down and draw nutrients from the water flowing past. It's all about flow, that's why it's a bit skinny. It's all interesting stuff. Someone might come along and say it's all wrong, but we're not experts, it's all about learning.