Congrats to all for trying Aquaponics. I can help with that part of it.
First and foremost is that you have to adjust everything for the fish. The fish really dictate the system since they supply the engine or the nutrients for the plants and believe me this nutrient really works. So the added nutrients that you use should be at the bare minimum. Which this is possible once the system is up and running properly. You could literally run this system with a solution of seaweed and kelp along with a solution of bat guano. You just have to be careful when you add supplements such as Cal-Mag or Silica among others.
Depending on the fish, you should keep water temp at no less than 60 degrees. I use Tilapia and they stop eating at any lower temps.
In order to deal with the amount of fish waste you have to create a Biofilter which is nothing more than a tub, 36 inches by 24 inches with 3/4 inch pea gravel and a bell siphon. Then you add red worms, red wigglers, and they consume the solid waste leaving the nutrient water.
Just some basics for you.
first off, duckweed, glad to see another ap enthusiast on riu!
yes, those are the basics and i tried it that way for about 4 or 5 crops and it grows shitty weed. the few other indoor ap cannabis grows i've seen online aren't anything to write home about either. i have yet to see an indoor aquaponic cannabis grow that produced a yield or potency (trichs) anywhere close to a "regular" hydro grow.
purist aquaponics is great for lettuce, greens, and vegging cannabis, but not good for flowering big, sticky buds. even with decent sized nugs for the wattage i was throwing at it, resin production was minimal with pure aquaponics. you get a ton of N and not nearly enough P and especially K.
i agree, vermipoinics is the holy grail, and i tried that too but not with this new system. honestly, i'm not after a purist ap system. i'm after a system that's tuned for churning out high quality cannabis. i may revisit vermiponics later. the red worms i used were thriving in the hydroton and reproducing, but when i tore down my experimental systems (4 of them), i lost the worms in the process. the problem with using food scraps was also that it attracted pests. bananas were especially notorious for introducing fruit flies into my room. i don't want to risk introducing any pests into my grow room, so fresh (or rotten produce) is simply forbidden.
fish will thrive in a wide ph and temp range. tetra, for instance, are known to tolerate ph as low as 4. not all fish can deal with this, but some will, and those are the ones you want. mine aren't jumpy and eat, sleep, and poop just fine. unfortunately, that means many fishies had to give their lives for the sake of my grow room, but i can live with that.
the fish are not the key to the system. the nitro bacteria are.
the fish do nothing for the plants. i could actually just pour ammonia into the system at this point to feed the nitro bacteria and forget about the fish altogether. the nitro bacteria displace pathogens that would otherwise cause kill a terrestrial plant in an aqueous environment. that's the ONLY reason i run aquaponics in my grow room. the extra nitrogen is just a bonus. feeding fish is cheaper, easier, and more fun than adding ammonia, so i keep them around
i'm not growing tilapia or any fish i plan to eat. the naturally selected fish are very well adapted to this environment and are thriving. when they get big, i turn them out to pasture where they can live out the rest of their lives in 7.0 ph 0ppm rain water in my outdoor "pure" ap system that i grow food and fish that i eat.
when you don't have to worry about slime and root rot, you don't have to do res changes, you don't have to chill the res, you don't have to sterilize, and you don't have to add bennies. all this fussing is just a normal part of hydro growing. you can take a lot of maintenance out of the picture once you get risk of root disease under control.
the optimal ph for nitro bacteria is 7.0-7.5. however, at that range, you will get scale (soap scum) as soon as a high phosphorus fertilizer hits the water with calcium in it. those precipitated nutrients will foul the roots and pump and eventually kill the plants and even the pump in a very short time. i've done it, multiple times, so i know. in pure ap, you're not adding anything, so high ph and nutrient precipitation are not issues.
dialing pH down to 5.2-6.5 range (i usually stay below 6.0), which is ideal for the plants, caused NH3/NH4 ammonia to shoot up to around 4ppm. i'm presuming most of the nitro bacteria died, but some survived and reproduced. successive generations of nitro bacteria further selected low-ph-tolerant nitro bacteria and now, many, many generations later, i have a nitro bacteria colony that is fully adapted to ph range of 5-6. the last time i checked ammonia, i had just a hint, barely registering. i have yet to test for nitrate, nitrites, but the fish, plants, and bacteria colony all seem pretty happy.
all that said, don't get me wrong: i love aquaponics and think it is the future of food production, but pure aquaponics has its limitations, especially when it comes to growing weed.
next grow i'm going to use general organics nutes only, so stay tuned. adding guano is a good idea too, but i'm trying to keep the amount of solids i add to my system to a minimum.
any plans for an ap cannabis grow, duckweed?.
