Backyard Aquaponics
A place to discuss aquaponics

The problem with vertical stacking is the shading issue. Let's say you're in an open field, and you have vertically stacked tubes for NFT. The shade created by the tubes and plants will prevent similar levels of growth horizontally until the shade ends. So you end up with the same plantable area for a given intensity of sunlight as spread out horizontally.

If, on the other hand, the geometry of your space is not open and level like a field, vertical stacking may make sense.

Also, you can increase the productive use of a space in the shade if you alternate with different crops requiring different levels of light.

Obviously, these considerations are site-specific, and so it's hard to come up with generalized rules.

Yea, if you are going to be growing indoors under lights anyway, I suppose you might as well stack provided it doesn't cause injury problems for the labor having to crouch to harvest the lower levels or climb on ladders to harvest the upper levels.

If using natural light, there might be some use for one lower level in a very bright location for growing plants that need some protecting and put the sun loving plants above. However, I expect this may be only seasonally useful.

Yes depending where you are the winter sun angle can make it useful to use vertical layout. In our area in summer the sun is directly overhead and there would be little advantage in vertical space, but in winter the angle is low enough that vertical rising can greatly increase exposure in less horizontal space. The same could be achieved with artificial lights.

One solution to the shading issue is to slowly rotate the vertical stack (say once per hour) so all the plants get an equal share of full sun and partial shade for even growth and no scorching.
Another bonus is the airflow over every inch of leaf surface (top and underside) as they move through the air. Wouldn`t be too practical for heavyweight gravel beds or dwc weight but maybe ok for nft.

I was actually thinking more along the lines of taking advantage of the added shade of the lower level during the hot summer. Come the cooler season more of the plants here actually want full sun while during the hot season, full sun is too much for most plants here.

Vertical is where we are going and have already tested (albeit with limited crop varieties). We are using indoor lights at 6,500K for the lettuce and basil. We will be soon switching to LEDs with a color mix of red and blue for all crops grown. Lettuce alone will not pay the bills since heads of lettuce sell here in the states for about $1 a head. The basil is much more financially productive. Would like to start with some other crops like Bok Choy and other varieties. For the fish, since they are also not a money maker and the regulations are ridiculous, we are thinking ornamentals like Koi, they are pretty hearty as well. I am trying to come up with the vertical tube concept for strawberries but don't yet know how I will handle getting the PH down to an acceptable level for the plants then have a healthy water return to the fish. I understand this is easy with hydroponics, but AP is the key to this endevour. We will also have growbeds for other crops but not many, NFT will be the majority of the system plan. This is a work in progress but we are really trying to see what and how much we can get out of an NFT system (done right ofcourse) to optomize yield times.

Yes, they are filled with gravel, and drip fed, but still work on the same flood cycle as the other GB's.

cheers