High guys,
We are starting 3 aquaponic cultivation sides and wonder if anyone has experienced what is the perfect ratio of fishes to plants so the plants have enough nutrients to grow without further fertilizer.?
Maybe there is a recommended density for the fishes? We will use Tilapia which are most common for Cannabis (followed by trout and perch for the ones who are interested)
Thanks!
Depends how big your system will be. Fish produce nitrites which can kill them if they accumulate to fast. From what I have seen slowly grow your system so it’s not a massive shock on the ecosystem.
I’ve played with aquaponics a bit with catfish. I started cycling with cheap goldfish because you will probably lose some until you get the right balace. Here’s a good video on stocking density:
I’ve seen some awesome customer setups because I sell a fulvic acid supplement. (No apologies for the shameless plug!) AGT-50 fulvic mineral complex chelates nutrients that are out of range for the plants. It helps the gut health of fish. It replaces kelp as a micronutrient source and supplemental iron as well.
Great thread!
I have done it for veg, works great. But fish waste is almost entirely nitrogen. The only instances I have heard of aquaponics working for flowering plants is if the fish water is mixed with a potassium and phosphorus source, then applied to the plants in a run to waste fashion.
I beg to differ that it doesn’t work for cannabis, tomatoes and other flowering plants. Is it an ideal nutrient ratio? Will you get the best yields? The answer is no, but you still get healthy plants with dramatically lower inputs in a self-sustaining setup.
Fish waste npk is 5 - .1 - .1, although I suppose every aquaponics could be a little different if other forms of life were added. Some people have snails, turtles, etc. I dont know the npk of every animal’s poop. The phosphorus and potassium has to come from somewhere, and fish waste has almost none.
I’m not disputing the NPK ratio. I’m disputing that you think it doesn’t work. I’ve got a customer using fish waste, fulvic acid and calcium carbonate as a pH buffer and is killing it with tomatoes. I talked to an aquaponic hemp farm in CO last week.
If anyone wants more information on doing aquaponics right, Murray Hallam is one of the most knowledgeable in the field.
I dispute that weed will grow without phosphorus or potassium, nor will tomatoes or other flowering plants. It has to come from somewhere.
You could always throw a chicken coop above the fish and get all the phosphorus you will want.
The P and K are in there, just not in the amounts you would like. It simply has to be available to flowering plants. You can get a better ratio by growing plants like lettuce in the same system that primarily consume nitrogen.
Murray Hallam and his papayas.
Then it isn’t fish waste any more, if he has processed it to remove the nitrogen. To get it to equal parts would be removing 98-99% of the nitrogen in the raw fish waste. And how much lettuce did he have to grow? What did he feed the fish? There are tricks behind that circus act, I suspect.
Amazing, the guy is exactly explaining what I was unsure of. Thank you!
No processing. Just fish poop, fulvic, and calcium carbonate. I filtered out the solids with a brillo scrubby pad and the beneficial bacteria took care of the rest.
Here’s a OMMP cultivation facility doing the same thing:
I’m sure bacteria play a big role in the cycling of P and K. Only looking at the fish waste is half the equation
Using plants to remove 99% of the main ingredient is still processing. “Pay no attention to the commercial lettuce farm behind the curtain.”
And the video was just buds. I am questioning the nutrients. Maybe it is possible to incorporate phosphorus and potassium into the fish food, but idk how the fish would feel about that. Maybe there is some other animal that poops p and k that can live in there.
For your average individual who wants to flower with aquarium water, it is much more practical to add a secondary fertilizer and not recirculate.
There are phosphorus and potassium fixing bacteria. Flowering plants can grow on just fish poop. There’s nothing nefarious or magic about it.
An old friend who used to live with me had a 3 part fishtank system that was so over the top. Anyways he decided to make it so that the waste water from the fish would go through a screen into a tank [that poop tank was usually always closed off from the plant tank] that had vacuum pressure from the plant tank bringing in water from the poop tank to the plant tank via diaphragm water pump from deschem. He had a manifold design so that the poop water can still be cleaned and the water sill circulated with an air stone setup. It was so fucking crazy
Anyways after about 14 failed attempts at growing weed in the tank due to nitrogen deficiencies and what seems to be chemical burns he decided to cut the efforts and decided to remove the plant section.
I’m pretty sure there’s a way to figure out some kind of isolation system to where you can do the same as my old friend did but make it so that the poop water can be vacuumed down to a second tank and then have it able to be read with some kind of water analyzer and wait for results. Then have that analyzed poop water vacuumed into a different tank that’s removable and this tank you could add nutrients and whatever the fuck. Which then THAT water gets vacuumed or pumped into a plant irrigation system.
Either way you’ll have to pH balance the fish poop water and make sure your npk is on point.
It’s actually a very high pH for plants to keep the fish happy- 6.5-7.5.
I thought of something similar which would use an ozonator to dissolve lots of 02 into the water. Then have a separate cycling tank with all the bacteria which eventually mixes back with the ozone depleted 02 water.
