Fish Manure as fertilizer?

I've just come across a rather significant fish manure source relatively close to me. It seems to be about 500 gallons per week of a mixture of fish manure and perlite. Currently, the business is throwing this resource into the trash.

I'm wondering if anyone here has expertise about fertilizer and compost.

Does this resource need any processing before being used/sold as fertilizer? Is it more appropriately used as a compost additive?

Thanks for the input.

I'm not sure what fish manure is. Is it a byproduct of some sort of fish farm? The only thing I would be worried about if it is from a fish farm is antibiotics/other weird chemicals being fed to the fish. Also why is it mixed with perlite?

stephen lowe wrote:I'm not sure what fish manure is. Is it a byproduct of some sort of fish farm? The only thing I would be worried about if it is from a fish farm is antibiotics/other weird chemicals being fed to the fish. Also why is it mixed with perlite?

Yes this is an indoor fish farm. My best guess is that perlite is used as a filter to catch the fish manure. Good point, I suppose that would be a wise question to ask.

In that case I would think that this would be a high nitrogen fertilizer along with other minerals. It would be a good addition to compost as well.

Mix it with wood chips and sell it as potting soil. You win from both the perlite and nitrogen. Thats a great resource. Are there any nurseries you could contract with locally to provide them with it? Potting soil sells at a premium.

Tj Jefferson wrote:Mix it with wood chips and sell it as potting soil. You win from both the perlite and nitrogen. Thats a great resource. Are there any nurseries you could contract with locally to provide them with it? Potting soil sells at a premium.

You think wood chips? My instinct would be to mix it with sphagnum moss and compost for potting soil. Do you have any experience with making potting soil similar to that?

Nope, I try to do everything super cheap and I get free chips, but maybe someone else does. I think mixed with the perlite and fish sludge you would have a fantastic potting medium in 6-8 months. we have been discussing wood chip composting on here.

You would definitely have to turn it a few times but I think you could have a great product in bulk. You would need somewhere around 8x the wood chip mass compared with the fish shmutz. I dump carcasses in the wood chips and it works, but takes more time. Yours would degrade very quickly. They are likely paying a tipping fee- and you should be getting a portion of that too. I could charge $20 a load for chips, but I take them for free because they know they had better be CLEAN or they will be back paying to dump. My suspicion is that they are probably paying around $60 a dump liquid like that in MA.

and yes, thats a lot of chips. Like hundreds of yards if you are getting 600 gallons a week. It is doable if you have the space. Potting soil sells for about $100/yard in bulk, so most places make their own from bark, coir, sand, perlite and peat or similar mixtures. None of those are cheap though, and most are not biologically very active. Additionally, there would be some (maybe a lot) of mycoremediation of the antibiotics if you used an appropriate fungal tea, if they are using them. you may need to protect your groundwater from getting contaminated. Definitely not something minor but something absolutely awesome to do for the environment if they are otherwise dumping this stuff.

I am making mine from composted chips and I add in 1/4 dirt. Perlite alone is pretty valuable, I wish I had that deal!

This could be a waste stream business! My hero!

Tj Jefferson wrote:Nope, I try to do everything super cheap and I get free chips, but maybe someone else does. I think mixed with the perlite and fish sludge you would have a fantastic potting medium in 6-8 months. we have been discussing wood chip composting on here.

You would definitely have to turn it a few times but I think you could have a great product in bulk. You would need somewhere around 8x the wood chip mass compared with the fish shmutz. I dump carcasses in the wood chips and it works, but takes more time. Yours would degrade very quickly. They are likely paying a tipping fee- and you should be getting a portion of that too. I could charge $20 a load for chips, but I take them for free because they know they had better be CLEAN or they will be back paying to dump. My suspicion is that they are probably paying around $60 a dump liquid like that in MA.

and yes, thats a lot of chips. Like hundreds of yards if you are getting 600 gallons a week. It is doable if you have the space. Potting soil sells for about $100/yard in bulk, so most places make their own from bark, coir, sand, perlite and peat or similar mixtures. None of those are cheap though, and most are not biologically very active. Additionally, there would be some (maybe a lot) of mycoremediation of the antibiotics if you used an appropriate fungal tea, if they are using them. you may need to protect your groundwater from getting contaminated. Definitely not something minor but something absolutely awesome to do for the environment if they are otherwise dumping this stuff.

I am making mine from composted chips and I add in 1/4 dirt. Perlite alone is pretty valuable, I wish I had that deal!

This could be a waste stream business! My hero!

This is all very exciting isn't it? My mind is racing with the possibilities.

Are you saying to spray the composting pile with compost tea in order to mycoremediate? I'm not sure they use anti-biotics, they seem to be a "progressive" company, will definitely find out though.

Do you think there could be any retail application for this potting soil? Like a bagged option say? Maybe then I would need to screen it for a more picky demographic.

Do you think there is any use for this material without composting it? It is either a thick sludge or just a very wet perlite type consistancy. What if I was to simply dry it out (I'm thinking large solar oven) and apply it as fertilizer?

Maybe even strain it and sell it as a liquid fertilizer or a powdered concentrate.  Like fish emulsion where very small amounts are used? If it is super high in nitrogen then selling it as a "concentrate" that gets diluted could save lots of processing time.

But I would be concerned about various toxins and bacteria and such. Maybe do some research and then take it to a lab to have it tested? You would probably need labs to be able to advertise/calculate the nutrient value and such too. I just recall hearing that some types of farmed salmon are the "dirtiest" forms of fish on earth.

Do you think there could be any retail application for this potting soil?

Yeah dude, I absolutely do and would fetch a premium compared with compost at $30/yard. Screening would be great, but it you are selling to a nursery they won't be quite as picky. That is a lot of screening.

Are you saying to spray the composting pile with compost tea in order to mycoremediate?

I'm thinking more https://permies.com/t/86002/Mushroom-Slurry-Garden]mushroom slurry. You could mix it in with the fish/perlite.

What if I was to simply dry it out (I'm thinking large solar oven) and apply it as fertilizer?

You would have perlite everywhere! I wouldn't probably be overly interested in it unless I was amending a compacted field mechanically (then it might be nice- maybe Bryant Redhawk will fill us in). Perlite is ~$20/yard, even if someone wanted to buy used perlite, and most people want sterile perlite for rooting. You have to remove the fish components from the perlite before it would have value, and then dry it. If it was easy the fish farmer would already be doing it, it probably isn't worth it.  For $20/yard, that is alot of work. By applying the whole mix to a carbon source, you are capturing the fertility and could (maybe) get a premium price. I think I overestimated on the amount of chips you would need, if it is just the captured manure. What percentage of the mix is perlite? You don't want a potting mix more than about 10% perlite. If it is mostly perlite with minimal residue, then it might be useful in propagating blueberries, which is a big business. Could also work with figs.

I still think it would be worth a shot with pure waste stream chips and maybe some sand/silicates (which should be readily available on the cape). If you can get a 10 yard load of chips, mix that stuff in and passively aerate it with some good ideas on here, you should know by middle of the summer what you have as a possible product, and have a sample to show prospective buyers. I am really hoping Dr Redhawk will show up to poke this idea, he has forgotten more in the last week than I know, and he knows the economics well. After people sleep off their eggnog there may be some more traffic.

Maybe even strain it and sell it as a liquid fertilizer or a powdered concentrate.

Lucretia, that might be useful, but my concern is that this producer has probably run the numbers and figured the juice/squeeze ratio is not there. Waste stream enterprises are tough. In terms of the testing, the fish farmer should be able to produce a list of all inputs, and if he can't I would be concerned. I would think getting the basic levels of nitrogen/macros would be pretty cheap and useful just to calculate what you are getting and ratios to mix for sure. A lab only tests for what you order, so unless you are looking for a particular contaminant, you won't find it. It takes a working relationship with the producer. That being said mycoremediation is very powerful. I have chips that I am sure get bar oil and hydraulic fluid and whatever else leaked into them. Fungi given some time will degrade nearly any organic molecule, and otherwise they are headed for the river/estuary or the aquifer. Tradd Cotter's book on this is enlightening, this is in my opinion something we can all do on a small scale for a big improvement.

I have access to aged fish manure from a local trout farm that doesn't use antibiotics or medicated feed.

At the trout farm the manure is pumped as a slurry from the settling basins to dirt pits where it sits and separates. The water is decanted and the resulting very thick sludge dries down into a dark heavy shovelable material (the color and consistency of 1/2 meter thick chocolate brownies). This stuff is put into empty fish feed sacks and provided free to the permies. In March I take 10 bags home and dump the manure into a pile next to the garden. In May I spread it on the garden and till it in.

I don't claim to have expertise in using fish manure as fertilizer but our garden produces a bounteous crop of veggies every year.

There are no weed seeds in this product and no human pathogens since it comes from cold blooded animals.

There are a lot of other much larger fish farms in our area. At least one company has turned their manure into a profit generating product. They mix their waste with used straw bedding from a large dairy. This mix is windrowed and turned over until it is compost. It is then sold by the large truck load.

Adam, does your fish manure come from a salt water farm or a fresh water farm? I wonder if it makes a difference.

https://www.facebook.com/pages/category/Product-Service/Meekers-Magic-Mix-125344670878677/

they ad sawdust\woodchips to fish manure, let it sit for a while, bag it and sell it. there are probably more steps than that, all I know is the more Meekers I use the closer my garden gets to Eden!

Adam, does your fish manure come from a salt water farm or a fresh water farm? I wonder if it makes a difference.

Yes it is a salt water fish farm. I wonder how concentrated the salt will be on the waste product. If it is a problem, I also wonder how I could remove it?

I don't claim to have expertise in using fish manure as fertilizer but our garden produces a bounteous crop of veggies every year.

I think it would would great as fertilizer too, I'm not sure how this attachment thingy works, but I've just tried to attach an image of the chemical analysis.

I've been toying with the idea of selling this material to local farmers to spread on their fields/orchards/vineyards etc. What do y'all think?

I still think it would be worth a shot with pure waste stream chips and maybe some sand/silicates (which should be readily available on the cape). If you can get a 10 yard load of chips, mix that stuff in and passively aerate it with some good ideas on here

Composting it with wood chip really seems like a great idea. I am somewhat space limited right now. If I do some good clearly to a section of this land I'd have access to somewhere near 1,000 square feet on a rather narrow plot. I am a little concerned about running out of room. Anybody have ideas on how much space it might take to compost?

Maybe even strain it and sell it as a liquid fertilizer or a powdered concentrate.  Like fish emulsion where very small amounts are used? If it is super high in nitrogen then selling it as a "concentrate" that gets diluted could save lots of processing time.

I don't think I'd want to separate the liquid from the solid. From my understanding of nutrient cycling, N tends to be soluble and moves into water readily but P stays bound up to sediment. This is such a high P substance and I want to retain that. Now I'm thinking if I did dehydrate it then the N may evaporate away. I think if I am to use it as a fertilizer, then I'm, going to have to spread it on the field or garden whole.

Does anyone know how much farmers pay for fertilizer per acre? I wonder what the difference would be between price of synthetic and natural and organic fertilizers.

I've also just found that they market themselves as "Antibiotic, Hormone, and chemical free". Lol I hate marketing like this because you can't have hormone free fish! Or chemical free water...water IS a chemical!!