New to this whole world of indoor growing and I see that vertical farming companies handle plant orientation very differently. Square Roots and Plenty looks to use zip grow towers or something similar to them while AeroFarms uses horizontal non-individualized planters. From what I’ve seen and read online I would think the towers require much more labor to plant in and have less growth per sq.ft, but I don’t have any data to support this. Does anyone have a paper that compares these two methods or even an answer on which on is more dense with something like lettuce or spinach?
It’s a bit of a complicated answer, but I would say it all depends on what kind of plants you are growing.
I’ve only been growing aquaponic for two years in a media bed setup so take it with a grain of salt, but from my experience and research I think raft system growing is the most space efficient for larger plants while zip grow towers are more space efficient for smaller plants.
The limiting factor in raft systems is the biofilter. The biofilter determines stocking amount of fish and the amount of nitrogen produced. The reason Raft systems are so effective is because you only have to space them apart enough to make sure the roots dont entangle and the canopy or foliage dont compete for light, and as long as the biofilter is big enough theres enough nutrients for the plants regardless of spacing for roots. That’s why they are better for larger plants such as tomatoes and peppers because the vertical growth can be trained and trimmed to ensure greater stocking density in relation to the amount of lighting you have, while ensuring all plants have the same nutrient uptake through the river system under the rafts as the roots can always grow further down if you have a deep enough river. You can then modify the design further by adding a media bed to use as your biofilter because you can grow shallow rooted plants in it while at the same time nitrifying the water allowing a greater number of plants in the system without sacrificing space. Using a media bed as the biofilter for a raft system also gives you the benefit of using worms to break down solid wastes so filtering isn’t as big of an issue while giving all the benefits of vermicompost and vermicompost tea to your system. A good example of this can be found on YouTube by searching, " How a Sustainable Aquaponics Farm Grows 7000 Heads of Lettuce a Week".
Now, for smaller plants I can see the vertical systems being better suited, although I have yet to try them myself. For plants that spread out in their growth such as spinach, chives, oregano and the like the vertical growing ensures they dont have to compete for light. Putting smaller plants in a raft or media system they would have to be spaced farther apart. The biofilter in vertical systems then, is the foam or filter inlay within the grow towers that serves as surface area for the nitrifying bacteria. So the limiting factor here is lighting. For instance, if you are farther north in latitude and growing in a greenhouse you are only getting southern light, and not getting any light from the north so you would only be able to effectively use half the grow tower as the plants would naturally grow around towards the source of light and crowd themselves. While you could probably get away with full growth during the summer this effect would be magnified in the winter. So to achieve greatest stocking density you would need supplemental lighting which may or may not be available. For indoor grows this effects your lighting options, for instance LED lights would work very poorly for veritical systems as LEDs are very directional and have little spread due to the diodes. While this is fine for a raft system where there is even spacing, the lights from an led may not reach the plants on the bottom of the grow tower. The only way to get around that would be to angle the lights or use different lights such as HPS or LECs, which then brings in the issue of airflow and cooling which could hinder your space requirements, as well as the lights themselves could get in the way of placing grow towers closer to one another.
So then, if you had the space and the lighting you could combine the two systems for maximum density by placing vertical towers above a raft system so that the towers drain into the river back to the sump and into the fishtank. In this setup the vertical towers would be taking in sunlight and the raft system would utilize supplemental lighting. Im having trouble copying the link, but an excellent example of this can be found by going on YouTube and searching “Vertical Aquaponics System use Bamboo Towers in Greenhouse to Increase Production 10x”
Hope this explanation helped, I may have rambled a bit there.
Excellent answer @pac013 , you definitely covered a lot of the up and downsides of orientation. Another thing to consider when choosing grow method is organic solids. I’m pretty strongly opposed to using ZipGrow Towers for aquaponics, simply because there are almost always more solids in the water of the system. The smaller drip-lines and regulating drip emitters are much more constricting than those on an NFT system and especially compared to DWC rafts. This leads to lots of clogging and system failure. I would love to see someone filtering enough of the solids out, but I’m not sure it’s worth it.
Overall for aquaponics I feel as though media bed is a great addition to the system because of the vermicompost like you said. Enough media-bed and biofilter to supplement your bacterial colony and then the rest of a vertical nft configuration & DWC would be a highly productive system.
Thank you for all the information. I am currently in the process of starting my very first grow and reading this thread was a blast of cool information. Would you happen to have any ‘dummy’s guide’ places I could watch/read about how to setup these self-sustaining systems? I’d love to get more information on the kind of magnitude in adding this to a system (as opposed to simply growing in the soil and water).
Look up Rob Bob’s Aquaponics on youtube, he has a lot of helpful videos