Liquid Fish Fertilizer – For Whole Food Nutrition
Fish and seaweed are often used together as fertilizer, and indeed, they’re somewhat similar.
They both provide broad-spectrum nutrition – not too much of anything, but a little of almost everything.
Where seaweed wins is in its natural plant growth regulators that help plants deal with various stressors.
But using fish as fertilizer does beat liquid seaweed in one way – it’s nitrogen content, and with many fish fertilizers, the phosphorus content.
Benefits Of Liquid Fish Fertilizer
Nitrogen and Phosphorus are two important elements that are often deficient when our soils aren’t yet up to par chemically and biologically:
- Nitrogen. Is the building block of proteins in plants, and ultimately in our bodies. We don’t need all that much nitrogen in the garden, but we do need a quality source, and that’s where liquid fish fertilizer comes in.
- Phosphorus. This element is important not just for root growth (as is the common myth), but it’s central to photosynthesis and building carbohydrates, and it’s involved with transporting almost every other mineral throughout the plant.
Plus, if you get a quality fish product, you’ll be getting oils, proteins, and enzymes that feed microbes and soil animals – that’s why I think of it as true whole food nutrition.
As with seaweed, I generally prefer a liquid form of fish fertilizer. Although fish meal definitely brings in some nutrition, some of the benefits are lost during its processing.
How To Make Fish Fertilizer
Get some fish and grind it up in a blender or food processor. If it’s a bony fish, you’ll need a solid machine.
Add enough water to cover the mixture and then process some more until it’s all blended up nicely.
There you go – you have a basic liquid fish fertilizer.
Now, you could use it right away by mixing it with 10 parts water and watering plants.
But to get more benefit, you can ferment it further so the nutrients will be more available for plants.
For that, I use 1 teaspoon of EM per cup of fish-water mixture, a 1:50 ratio.
If you don’t have that around, other kinds of probiotics will help.
Then, add 1 teaspoon of sugar per cup of fish-water to give the microbes an energy source.
Put the whole mixture into a container with a lid or towel over the top, but don’t tighten the lid because there will be gases produced that could cause the container to explode.
After a month, the smell will have decreased in intensity, which means the fish has been consumed by the microbes and your fish fertilizer is extra special and ready to go.
Finding A Quality Liquid Fish Fertilizer
There are so many fish fertilizer brands out there, it’s hard to keep track of them.
I recommend a fish hydrolysate fertilizer instead of a fish emulsion fertilizer:
- A liquid fish emulsion has had most of the fats and proteins removed for other uses. It’s cooked at high temperature, which destroys vitamins and enzymes. Also, chlorinated city water is generally used, so the end product is often high in chlorine. An example is the (unfortunately popular) ‘Alaska Fish Fertilizer’ made by chemical company Lilly Miller, which comes from the polluted Gulf of Mexico – not Alaska.
- A hydrolyzed fish fertilizer retains the fats, proteins, and enzymes because it’s processed at a cool temperature. A good hydrolysate will have this done before all of the bones, oils, etc. have been removed, when the fish are still fresh. Hydrolysates don’t smell nearly as bad as emulsions, which tend to use rotting fish, and they’re usually filtered better so they don’t clog equipment as much as emulsions.
I don’t mean to imply that a fish emulsion is useless – it’s still a worthwhile fertilizer. But put it this way – people who switch from an emulsion to a hydrolysate are often going to be happy, while people who move in the other direction are not, i.e. the difference is noticeable.
It’s like freshly-picked vegetables vs vegetables from a can.
A good hydrolysate is usually $20-$25/quart. I’ve seen a few at $10-$15/quart, but they’re usually using fish from polluted rivers (like the Mississippi) or lakes (like the Great Lakes) or they’re using farmed fish, or they’re creating a liquid fish emulsion fertilizer and then adding enzymes back in after so they can call the product ‘hydrolyzed,’ but still, many of the beneficial components of the fish will have been destroyed or denatured during the processing.
I prefer ocean fish from unpolluted waters. Organic Gem is a good one.
And Neptune’s Harvest is the one I settled on because I like everything they’re doing:
- With many fish, when they’re processed for food, most of the fish is wasted. Neptune’s Harvest is taking that waste and making use of it rather than dumping it back out at sea. Others are catching fish just to make fertilizer, which doesn’t sit quite as well with me.
- They’re fishing off the northeastern seaboard of the U.S. and they’re doing so very sustainably. It’s true that some parts of the world are overfished and some fish are overfished, but that area is being substantially underfished, not overfished.
- The fish come from the deep, cold, mineral-rich waters of the North Atlantic ocean, not from polluted areas near the shore or rivers or lakes, or from the Gulf of Mexico.
- They’re using many different species of fish, which conceivably makes for a more well-rounded fertilizer, although I suspect that’s less important.
As with most organic liquid fish fertilizers, they’re using a touch of phosphoric acid to drop the pH, because otherwise, the microbes in the product can get so active that the container might explode.
Phosphoric acid is the same stuff they use in Coca-Cola and it’s not great for us to be consuming, but in the garden, it’s VERY useful. This little amount is allowed in organics (indeed this product is OMRI-Listed), and I would strongly prefer to have it in there than not.
How To Use Fish Fertilizer
Shake well before each use because sometimes there’s a thick part that separates out.
Once you’ve mixed with water, use it the same day.
Since I also use sea minerals fertilizer, I alternate them every other month (eg. fish in March, sea minerals in April, fish in May, etc.). I use seaweed every month along with them.
In my garden, per 1000 square feet, I end up using 1/2 cup of liquid fish fertilizer, 4 times per year.
That works out to nearly 1/2 quart per 1000 square feet per year.
If I wasn’t using sea minerals, I’d spray it 8 months of year, which would be 1 quart per 1000 square feet per year.
If you want to spray it weekly, use 1/8 cup (2 Tbsp) per 1000 square feet instead.
The dilution rate can be between 1:50 and 1:100. I go with 1:50, which is a gallon of water for every 5 Tbsp of fish. I just use a hose-end sprayer set to spray 5 Tbsp per gallon.
Here are their suggested application rates:
- House Plants: Use 1 tablespoon per gallon of water every 1-2 weeks.
- Outdoors: Use 2 Tbsp per gallon of water every 1-2 weeks.
- Lawns: Use 1 gallon for 8000 sq ft every month.
- Seeds: Use 1 teaspoon per cup of water for soaking seeds.
- They suggest applying until the soil is saturated or as a foliar feed until the leaves are wet.
They recommend 3 gallons of product per acre, 4 times per year. That works out to about 1 quart per 1000 square feet per year.
You Can Get It Here
In summary, this liquid fish fertilizer:
- Provides many benefits, but is especially known for providing nitrogen and phosphorus that promote rapid plant growth, as well as the complete fats and proteins that microorganisms need.
- Is a hydrolysate, processed with enzymes at cool temperatures in order to retain all of the beneficial components.
- Is organic, OMRI-Listed, and not even too smelly.
- I ship in the U.S. only. I ship 7 days a week.
- In the continental U.S., shipping is $15.
- All of my products have a 1 year 100% money-back guarantee.
- If you have a question about a product, leave it in the comment section below I'll try to respond within a few hours.
- Dry fertilizers and compost tea brewers ship separately so they will arrive on their own maybe a day or 2 apart from my other products.
- I send a percentage of every order to Thrive For Good and other similar organizations. They're working mostly in Africa to help communities grow organic, medicinal food for themselves, and then use the surplus food to generate income for themselves as well as feeding the orphans in their communities.
Hi Phil, I’m just a little concerned with using ocean fertilizer products due to the fact that most of the oceans have pollutants, as well as nuclear. For this reason I do not consume any fish or sea products. What are your thoughts?
Great question Rick. I was very concerned about the nuclear issue, too, so I did some digging and I’ve now come to believe the danger has been overblown. Certainly in the water by Japan there is much toxicity right now, but it seems it is not making its way to the U.S. in high concentrations as is often reported. It really seems to be an acceptable amount coming over here. I’m pretty strict about this kind of things and I’m all for the precautionary principle, but I believe this isn’t something we have to worry about.As for fish, like you, I don’t eat it, due to heavy metals and other issues, but I am not so concerned about those heavy metals transferring from the fertilizer to the food I grow. It’s definitely something to think about, but I’ve never been able to find any good information about what would be considered acceptable levels of heavy metals in these kinds of fertilizer products. You can find the levels online – I just don’t know how much of them will transfer to food. Note that most of my products are OMRI-Listed for use in organic production, including this fish, which makes me feel better about using them, although I’d still love to learn more.I do tend to use my sea minerals fertilizer a little more than the fish these days, just because I believe it’s more sustainable. And while heavy metals do end up in fish, I don’t worry about it in the ocean water fertilizer. They are present only at very small levels there, because they don’t get concentrated like they might in fish.Hope that at least partially answers your question. Perhaps some day I’ll write a blog post with more detail.
If it’s the same Sea Minerals product I’ve been using for the past 12 years, then it is from the Sea of Cortes and harvested from the salt that collects in inland pools on the shores of Baja, Mexico. Dr. Murray chose this location due to the greatest diversity of sea life and the highest concentration of Sea Minerals. I’m referring to the dry product. I don’t know where they collect the Liquid version. I much prefer the dry over the liquid. It’s much more cost effective as I don’t have to pay for shipping costs on the 8 lbs. of water per gallon of product.
Hi Phil,How much should the fish fertilizer be diluted for use on indoor seedlings? I put some in my tomato seedlings and although the plants appear to be happy, there is a white fuzz on the top of the soil with some of the plants. Is that a problem?Thanks,Cathryn
A 1:50 dilution should be plenty diluted (5 Tbsp per gallon of water). White fuzz is probably a mold, usually because of overwatering. It’s not necessarily the end of the world, but definitely nice to not have it there. If watering less doesn’t help, you might want to re-pot in new soil. Spraying EM/SCD Probiotics might help, too, or top dressing with a bit of good compost.
Thanks Phil! The white fuzz is only showing up on the soil of the plants that received both seaweed and fish fertilizer combined together. Some received only the seaweed fertilizer and they have not developed the fuzz. All the plants have been watered the same amount, so I am just curious about why there is a difference?Also, just to clarify…is the 1:50 dilution for the garden plants also? Or just for the seedlings? I believe the bottle says 10 ml per 100 ml for soil application. Just wanted to check that with you.Thanks for the great site and advice!
Oh, that’s interesting about the mold being caused by the fish. It is known to be a good fungal feeder when making compost tea, so I could see it encouraging the mold. I suppose applying with a higher dilution and/or applying less often might curtail that, or just foliar spray instead.You can certainly follow their recommendations for dilution rates. I had come to 1:50 by looking at their farming rates, but I know they actually promote a higher dilution (1:128 for the garden and 1:250 for house plants) on their label, which is certainly a safe bet – never hurts to go more diluted. I’ll update my instructions up above at some point.
Thanks again Phil! I am hoping I didn’t overfertilize the seedlings. I checked the bottle again and it says 100 ml per litre for soil, which I figured out to be 6 and a bit tbsp. I thought that was a lot so I cut back, but still used 4 tbsp in two litres of water, which is more than the 1:50 ratio you mentioned. Hopefully they will be okay 🙂
Hi Phil:Have any of your products been used on bonsai plants, or have you had inquiries from bonsai people? How would I use your products for bonsai. Would your products be too acidic? Thanks.
Good question Charles. I’m not very knowledgeable about bonsai, and haven’t had inquiries. The mycorrhizal fungi would be useful. I think a dilute solution of the seaweed and/or sea minerals would be useful too, as well as effective microorganisms, which seems to have the potential to be universally helpful. As for the fish, it may very well be helpful, but I don’t know if the big hit of nitrogen is necessary for most bonsai plants – that’s why I lean to the seaweed/ocean water.
What is the best fertilizer for a jacaranda tree. I wanted to buy the fish fertilizer but it has high nitrogen and I was told too much nitrogen makes jacarandas not bloom. My jacarandas are not blooming.
There’s actually no such thing as a ‘best fertilizer’ for each tree. The best fertilizers are the ones that fix the deficiencies in the soil and tree. But I will say that fish is fine for your tree. It has a small amount of nitrogen, not too much. It also has phosphorus and many other important nutrients for blooming.
Hi Phil – a soil test told me that P is excessively high in my beds, so I am being careful to not add more. Will my veggies be getting enough P from the soil in these beds that I do not need to add Fish Fertilizer? Would I be better off with only the Seaweed Fertlilizer? (The Sea Minerals sounds wonderful but is a bit too costly for me this year)
Hi Ivy, good question. Whether or not your plants will get enough P from the soil depends on how ‘available’ the P is in your soil. The soil tests that I use will tell you that, but most soil tests don’t. The bottom line, though, is that the small amount of P in fish fertilizer is not going to cause any excess, so it’s still 100% okay to use.
Thanks very much for your response, Phil! I do not see on your website anything about the soil tests you do (pricing, etc). Where can I find it? I think I’ll send some soil in to you next spring – or perhaps this fall would be better.
I don’t do them Ivy. I recommend that samples be sent to organic labs such as Crop Services International or International Ag Labs.
Hi Phil, is it ok to use the fish and seaweed fertilizer on leafy vegetables such as spinach, Asian greens, kale and collard greens? I worry about how they will affect the taste?
Yes, it’s fine. You just want to wait a while before harvesting. Not sure how long but I’d say a couple of weeks is sufficient.
For a lawn: Would switching from big box store chemical lawn fertilizers (with high nitrogen, often zero phosphorus, and sometimes a little potassium) to regularly fertilizing a lawn with liquid fish (2-4-1) like the one you suggest, provide too little nitrogen and too much phosphorus (causing ecosystem damage due to phosphorus runoff )? I could compliment this with molasses, EM, liquid seaweed, and/or sea-minerals. why would your recommended liquid fish be better than the 5-1-1 in the alaska fish fertilizer that I see you are not fond of?
Hi David, good questions. Whether switching to fish plus these other products will work depends on multiple factors, like how healthy is the soil food web, how much organic matter is in the soil, do you leave your grass clippings on the lawn to improve the soil, etc. You could run an experiment on your lawn, sticking to the old way on part of the lawn and then trying the new way on another part. Again, it depends on the lawn, but there’s a good chance the new strategy will actually work better than the old one.
No, there won’t be nitrogen/phosphorus runoff with fish because we apply it in such small amounts on a more regular basis.
As for fish, it’s not that emulsions are bad but they’re generally not as good as a hydrolysate because many of the nutrients, oils and proteins have been removed. Emulsions do have more nitrogen but less of many other things. And having more nitrogen isn’t inherently good or bad – it just depends on how much nitrogen you need. A lawn with decent organic matter and where the grass clippings are left to improve the soil shouldn’t need much (if any) extra nitrogen.
I have Alaska fish fertilizer. It was recommended to use on a privacy screen of sky pencil shrubs. I have about 20 of these plants about 4 1/2 feet tall. I am thinking of using a 2 gallon jug/sprayer and was wondering how to apply. On the bottle it says 3 tablespoon per 2 foot plant height.Is this the correct application for this product and these plants? It seems like that’s a lot. I’d love to know what you recommend. In the future I will try Neptunes harvest but unfortunately I Currently have this. Thanks for your help and words of advice in advance.
Hi Kristin, I don’t use it so I’m not sure but you can certainly do what the label says, and if they give a range, it’s not a bad idea to go with the low end. Or if they give a dilution rate, you can focus more on it and just spray the leaves until they’re dripping.
Hi Phil, thanks again for the great service on my order. I will be working with all container plants, including a few tomato plants in 15-gallon nursery pots in the backyard, along with petunias and red geraniums in containers on my front porch. If I mix the BioAg together with fish fertilizer and/or seaweed fertilizer, using your calculator, once a week, is it ok to use the fish and seaweed together at the same time? The calculator gives me amounts for each one. Or do you think it would be a better idea to rotate, fish one week, seaweed the next? Either way, the calculator gives me the same amount for each, even when I use both of them at the same time.
I use them all together, and yes, the rate is the same for the Neptune’s Harvest products. You’re good to go!
What is the ratio when using dry fish fertilizer?
Does it say on your label? If not, can you clarify your question a bit for me? Thanks!
The label is not available. Contents have been transferred to another container. Any close approximation will be of help.
It’s generally used dry, mixed into the soil. I’ve seen anywhere between 2 and 10 pounds per 100 square feet, depending on the product. To make a foliar, I’ve seen 2 Tbsp/gallon of water, but I’ve never seen how much of that fish-water to apply. I would just water normally with it.
I don’t know if this is the right page for this but is the 10oz powder the same as Maxicrop? I think their seaweed powder was Ascophyllan nodosum, or something similar. Thanks.
Mine is made by Thorvin and yes, although I hear the quality of Thorvin products is higher, it is a similar product, from what I understand.