This week in the Flog:
- Making Fish Fertilizer
- Photos to go with the recipe!
Some time ago I finally ran out of the fish fertilizer I made last year. Time for a new batch! I documented the process for all those interested in seeing this awesome recipe in action!
Homemade fish fertilizer is an organic fertilizing solution that allows you to move away from petroleum-based commercial fertilizer. It is made from fish which is one of the very best sources of macro- and micro-nutrients for healthy growing plants. You can make it yourself with very limited resources. And it is SCENTLESS. We have an awesome recipe on how to make it here.
In my current living situation, I don’t have the time or space to get a good source of fish waste and make the recipe that way, so I’m just buying a tilapia from the market to use. It’s a nice size fish, and using the whole fish means the end product will be that much better:
Now the bloody work. I’m chopping the fish up into smaller pieces and then into the blender they go. This is a pretty messy process and I would encourage you to do it *outside*.
Now before I blend up the fish, I’m going to add the water and sugar. The fish is a little thick to blend on it’s own so I add the water before blending – and adding the sugar now allows the blending to help dissolve it. I’m adding 1L of water, a little less than what our recipe calls for but no matter, there is no real right or wrong here. I’m also adding 150g of sugar – 1/3rd part sugar to tilapia.
Now this whole mixture gets blended up really well. Only takes about 5 minutes or so of blending/pureeing.. My cheap blender has a little trouble with the bones at first but after awhile it’s pretty well blended. Check out the blended goop:
Last step – add the lacto. I’m adding 2 tbsp of dilute lacto serum – there is no rule here, I could have added more or less no problem. But 2 tbsp for this amount of mix is about right in my book, maybe a little on the heavy side which I like.
Now I just blended it enough to get the lacto mixed well, and then this goes into the fermentation vessel. In classic Gentry style this is a plastic juice jug. Your fermentation vessel doesn’t need to be anything special as you can see from mine, haha. But it should keep the liquid as anaerobic as possible. For most people this means installing an airlock in the container. An airlock, used in wine and beer production, allows air out but not in, keeping the inside oxygen-free.
Whoa! What is that blue tube with the hose going into it?! It’s a homemade carbon filter I added to the system. It’s not 100% functional for what I want from it, but it does cut the smell completely. I know a number of people complained about the smell during fermentation. I’ll post another article on how to make your own carbon filter, then you don’t have to worry about the smell anymore. This also works well as an airlock.
If you’re curious about how fermentation is going, watch your airlock for bubbling. In my case my airlock is the carbon filter with the little outlet tube. So for me to see, I dip the end of the tube in some water. And what do you know – bubbling away! This indicates CO2 and other gases are being released through the process of fermentation, and is a great sign of a successful fish fertilizer production.
Now let’s skip to the end of fermentation to see the good stuff – final product! Fast forward 3 weeks. In the warm weather of the tropics here in the Philippines, this is more than enough time to complete fermentation. To bottle up my fish fertilizer, I’ll use a strainer and funnel, and pour it out of the jug right into the storage container.
Here’s the great thing, it’s SCENTLESS. Very nearly anyway, and the smell it does have is like wine, like a fruit wine or something, it’s wonderful. I mean wonderful compared to how it smelled going in. Fermentation really does some cool stuff. Who would have thought a rotten fish could have no smell.
Another cool thing, what’s left in the strainer! We started out with a nearly 1 lb fish. Scales, gills, bones, skull, everything went into the brew. It was blended initially and that helped dramatically to break up those big bones and increase surface area for microbes to work on. But there were still a lot of large bones at that stage. Now look at what’s left in the strainer after I’ve emptied the jug:
Amazing! Around 2 tbsp worth? Tiny! Out of that whole big fat tilapia, we end up with a little tiny pile of bones. And they are different. They aren’t brittle, they are soft and rubbery. They are clearly degraded, and will break down in the soil in no time. I added these directly to one of the planters.
And now you can see the fish fertilizer in it’s final jugs – more recycled plastic containers. I ended up with about 1.5L of fish fertilizer from that fermentation. This will be great for my plants, they need a bit of a nitrogen boost.
Pretty cool stuff. It is really fun making your own fertilizer and seeing how fermentation produces such dramatic results.
I use this fish fertilizer in many applications:
• 2-4tbsp/gal in water for plants to green them up (normally just 2tbsp/gal but sometimes more)
• 1tbsp/gal applied to the compost pile, nitrogen boost and microbe feed
• 1-2tsp/gal in aerobic compost tea (very small amount as the oil tends to reduce aeration)
• 2-4tbsp/gal in anaerobic compost tea (or even more, there is no limit here)
• 0.5tbsp/gal in water to moisten animal feed bokashi prior to feeding worms/roaches/dog
There are all kinds of applications for this stuff as you can see in the list above. It is not only amazing as a direct fertilizer, but also as a microbe food source, nutrient source for large animals, and more. Get creative and play with it around your house. It is awesome stuff!
Keep on growing.