I had an idea and was wondering if it could work.

I'd love to build a small pond for raising bait but that's just not going to be able to happen anytime soon right now. In the meanwhile I was trying to think of other ways I could raise FHMs.

One thought was to build a cage that is in my pond, maybe floating next to the dock or along the shoreline. If I made it 6x6' or 8x8' by two or three ft. deep, (big enough for a stack of 2 or 3 pallets, corralled it with 1/8in. mesh, and put a top over it, could this work? How small would I need to make the mesh to keep the young inside? Would 1/8" be too small and need to be something more like window screen?

Would this be a waste of time? If worth a try, how many minnows should I initially put in it? I assume I would be feeding them fish food.

My other idea was to use a small pool, about 8' diameter and 2 feet deep, put it in the shade, run aeration in it and see if minnows would work in that.

I don't know about your cage idea.

However, here is a link to a Pond Boss thread discussing your second idea about a tiny FHM pond.

Tiny Fathead Minnow Pond

Good luck,
FishinRod

Sherwood I like your idea someday I might do something similar ... But I have some things to add.

1. I wouldn't try to raise fry to adult in the cage. I think the best approach is to use the cage to seed your pond with fry and just let them grow to whatever size they are able. Your pond can support a very substantial weight of fry and juvenile minnows at various stages of development. Yes they will be eaten by BG and LMB .... but that is point right?. So just try to protect the brooders in the cage so they can make babies. IMHO the mesh should be large enough to allow new hatched fry to go their merry way and small enough to keep brooders in and predators out.

2. Keeping screen clean enough to allow water flow through it is important. Might be pretty tough to do in full sun so is there any way it could be fitted under the dock and fed through the dock in some fashion?

3. You mentioned a kiddie pool and again there is a limit to the number of fry that can be grown to adolescence or adulthood ... BUT ... if you collect eggs and hatch them you can stock free swimming fry into you main pond. Here's a good reference in case you are interested.

SherWood, I seem to recall that the Floating Island folks had some success building habitat protecting FHM. At least, this was hinted at not too long ago. You might inquire with Bob Lusk.

I myself have purchased a large fish cage and used it to house CNBG that I later stocked in my forage pond. Wonder if 1/4 or even 1/2 inch openings would work, especially if FHM spawning surfaces were placed in the cage. Would need to keep out coons, turtles & herons as well as predatory fish.

I like your idea in #1.

Yep, my goal would be to breed minnows to move into the pond for forage without having to continue to purchase and travel for more minnows.

As for the pool idea, I would need to buy one that has some size to it but I don't want something that I'd have to pay hundreds of dollars for. If it's too small though, it won't be worth my while as far as raising much forage but it could at least provide a learning experience that helps me figure out exactly what I may want or need. Another pool type of option would be to build a small pond/pool with a liner, kind of like a backyard koi pond sort of thing, minus the koi of course.

Yup, whatever I would do, I'll have to keep varmints out, including my ducks. If I am going to raise FHMs, I will have to use something that's big enough to house some structure for them to spawn along.

When I was a kid, I had a box turtle pen in my backyard. It was probably 12' by 12' with a short board fence around it, no more than a foot high. It was low enough that they would get out of it at times and I'd find them in the nearby strawberry patch.

My dad built a tiny pond in it with concrete. It couldn't have been much more than 3' by 2' and no more than a foot deep. I used to throw minnows in there I'd catch from a creek and never remember having a fish kill (except that one time when I added a small snapping turtle to my turtle pen.). I don't think they ever produced young and I never used aeration or filtering and don't even remember feeding them. I also recall a friend of my dad's who kept minnows in his backyard in a small rowboat that filled up with water.

After taking some time to plan out a small pond or pool idea to raise minnows for forage, I'm beginning to really warm up to the idea of doing an in pond cage instead of a pool.


If I do it that way, I won't have to bother with aeration and hoses as well as figuring out how I will power my pump. I would also have to build a sturdy platform to keep it level, as well as pay for all of this stuff and keep a pool operating. If the young minnows can freely exit the cage, that will save me the hassle of having to do it myself.

I can put the cage under the dock but extend a portion out to where I can put a door on the top so I can access the cage and sprinkle feed in it without having to drag the entire thing out from under the dock. I will still make it where I can pull the whole thing out as well. I'll make a wood frame and use wire mesh. Does 1/4" mesh sound right? I'll need to affix floats to it too.

My walkway is pretty much the only place I will be able to put it. There is too much obstruction to under the main dock. So if my walkway is 4' wide, I can make the cage 6' x 6' and up to 3' deep. I hope that's a big enough space for this to be worthwhile. I have no idea how many adult minnows it can hold and I don't know how I would have any idea of how many fry are being produced and swimming out the mesh and into the pond. That's one big downside as I don't know if I can judge whether the system is working well. Also, hopefully there's enough fry being produced that they have some chance to grow a little before being gobbled up so they can at least make a difference as forage.

This would be an awesome way to supplement feeding for a pond if it will work and produce at least a meaningful amount of self replenishing forage.

Even if fry are being consumed as soon as they exit the pen, you are still feeding the system. Many ways to look at this, and adult FHM are just a step on a huge ladder 2/3rds of the way up. everything from the bottom up needs to be there to work.

Just realized that I know nothing about minnow spawning/nesting. How will they “nest” in a wire pen?

Good point Snipe. The setup likely won't be in vain.

I am thinking that I may set up a small test cage in a sizeable baby pool I was using for my ducks, although I'll have to situate it where they can't get to it. I will put a fraction of the thousand(s) minnows I purchase (100 or so?) in that to see how much they are producing and what the fry do as far as remaining in or leaving through the mesh.

I have the week to get this stuff constructed and can pick up the minnows next weekend. I wish I had the time to get er done after work today and tomorrow morning because now I'm antsy to get this going but I will spend my time and not do a sloppy job. Who knows, if it works well enough, maybe I'll build a couple more and put them along the other ends of my pond.

I'll check back and let people know how things are going.

I've tried keeping FHM in a wire cage in the pond. After a few days they start to look pretty rough - rough meaning large numbers of
them have torn their faces off trying to find a way out.

Think about using a nylon mesh enclosure rather than hardware cloth.

Dang, hate to hear that but it was something I had wondered about. Thanks for the tip!

Is 1/2" x 1/2" too large for FHMs? Am I going to have to go with 1/4" mesh for sure?

Even your jumbo adult size FHM will come and go as they please if 1/2" mesh is used.

1/2" x 1/2" holes is too big to keep them all in the cage except for maybe the largest of the adult FHM's. 1/4" square should be fine for breeding size adults, but would let the teenagers out.

+1 on the hardware cloth being hard on the fish. I did the same thing while culling fish from my pond and within a few days of being in a steel mesh cage...some of their eyes were cloudy from rubbing on the mesh, not to mention the scale scuffs and scratches.

Here are some knotless seine webbing that would be more fish friendly.

This one also carries a nylon mesh.

This other one only carries polyester in the smaller knotless meshes.

How will you keep the FA from growing and clogging the water movement through the cage material?

Hmmm, another thing I haven't considered. It's nice to have others help troubleshoot potential problems before I build this thing so I don't spend too much time and money on something that is doomed from the onset or needlessly troubled. Like with the galvanized hardware cloth, I may have purchased and used that material without realizing just how harmful it would end up being on the minnows if it wasn't brought up here.

I guess I'll have to maintain the cage and clear any obstructions that may arise if it starts to become a problem. If I make it, I plan to do it so that I can move it around. I'll limit the size to something I can handle or make two smaller ones. Currently, our algae appears to be on the decline and is mostly situated near the banks. If it becomes too big of a problem along the walkway, I can possibly move the cage out to the deeper end of the dock. I'll have some floats attached and I could put a cover over at least part of the top to provide some shade. I do plan to fully cover the top with whatever netting material I will use too. I'll probably make it such that I can open the entire top and then also include a smaller trap door entrance in the top.

Thanks for those links. I've been looking online today for something in 1/4" that may work for me. None of the hardware stores in my area carry anything I would want. What do you all think about PVC coated wire mesh? It's hardware cloth with a vinyl coating. It would be sturdy and tough but I don't know if the fish would still injure themselves on it like some of you've experienced with normal wire mesh.

I think the pvc coated wire mesh maybe better than webbing (no worse for injury but possibly longer lasting). I am trying to remember who used webbing to construct a cage here. He could say more about how well the webbing stands up. The PVC coating substantially increases the life of wire in water while softening and smoothing out the rough edges, so I think it is a worthy choice.

I have a vinyl coated mesh cage (about 18"x18"x 24" with 1/2" holes) that I have used to hold crawdads for the last 3 or 4 years. It stayed in the pond from April to September each year and has held up incredibly well, no signs of rusting away anytime soon. This stuff is pretty stiff and no way of rolling it up in it's flat form...it's a heavier gage wire at any rate. If you could find it in a smaller hole size, it would be my choice for a minnow cage. I would make a round, obround, or squarish with rounded corners coral with a flat bottom and add stiffener bars (think light rebar) if needed. Something like this shouldn't be too difficult to brush off with a broom to keep it clear in case the FA was a problem. The roundness of a coral would help keep the fish from fighting a corner while looking to get out. I used hog rings to hold the panels together on my small cage.

With the mesh cage, get a deck scrubbing brush and scrub the mesh on the sides of the cage. That will remove any FA that forms.

I have plastic cage netting that has held up for 10+ years without any degradation from the sun. You can get it here:

https://www.industrialnetting.com/cage-netting.html

I ordered PVC coated 1/4" hardware cloth. Hopefully that will work and I'll monitor the health of the minnows after I build and use my first cage. If it turns out to be less than desirable, I can still find other terrestrial uses for the cloth as I am constantly using that kind of material and chicken wire for other projects. If I ditch on that, I'll get some kind of netting that is softer and more pliable.

I think I will build a square or rectangular shaped box but will round the corners.

One idea I would like to use that I hope will work for breeding spots is to add a bunch of cut pieces of corrugated 3" or 4" tubing inside. I don't know what size diameter would be best and also am wondering if I need something with a rougher surface area for the eggs or if that would suffice. If I can go with 3" tubing, I can fit in more spawning spots. Also I can get either solid or perforated walled tubing. I am also unsure how long I should make these tubes, 4", 6", 12"? I don't know what would be more effective for breeding and egg laying while also trying to utilize as many locations for them as possible.

Consider using light PCV pipe for the egg laying, and/or the corrugated plastic sheet that cheap signs are made of. Both are light and I have seen other's success with regards to holding eggs (in aquariums). As far as size of either, I'd try items that are at least a foot long (or a foot square) an no more than 3 foot.

A male FHM tries to lay claim to an area that is about 18" square whenever possible.

This is good stuff to know and I'm glad to get valuable input on the questions I ask. Thank you!

So that means that my space available inside my cage will be at a premium. I likely won't be able to expect an enormous number to spawn at any one time unless males allow more than one female to come lay eggs in their defended space.

I sounds like layers stacked on one another may be a better choice than tubes, although the tubes will also have areas and surfaces inbetween and outside of them. Still though, at 4" wide, it may make things tight without much wiggle room inbetween. Layering/stacking surfaces may be the way to go.

If you are interested I built a FHM "condo" for my RES/SMB pond to give the FHM something to spaqn on. It was not in a cage but instead staked to the bank of the pond. But it might give you some ideas.

Did it work? Darned if I know. I got the idea from some youtube videos on FHM or Rosie Reds spawning in aquariums. Several people were using PVC pipe as a substrate for them. So I got the idea of making a colony of PVC pipes. I tried to turn the pipes different directions to give the couples the most privacy and minimize competition. The holes drilled in the pipes were for water flow and good aereation (at least my idea of it).

Scroll down the page to where the title includes the words "some FHM substrate. 2/3 the way down the page. The installation of it in the pond is further down that same page.

https://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=459159&page=6

I like that "condo." I put together a couple of pallet stacks out there before my pond filled up but now wish I would have put more. I also put a few brush piles of mostly cedar.

I think for the cage I could go with a combo of pipes between layers of wood. My thought right now is that the cage will be about 4ft square. I want it small enough to move around and service as needed. I probably won't have a lot of room as I will likely leave a gap in the middle for a minnow dip net if I want to try to take some out without first removing the structure.

If my cage is 4 ft. square and either 2, 3 or 4 ft. deep. I wonder how many minnows I should put in it? I wonder what the limit will be such that they become a constant menace to all who are trying to guard eggs. Will they destroy one another's nests? I'd like to stuff in as many as possible.

I will be making another tester cage to keep in a large pet or baby pool to see what kind of production I can get expect.

What if you approach this from a different angle.

What if you make your cage and only put in a handful of FHM's? Maybe a couple dozen. However many could have spawning areas they could protect. Size the mesh of the cage so the breeders stay in (and anything that could eat them out) and the recruitment (babies) wanders out into your pond.

Provide cover and habitat for the fry around the cage.

Could it be you would get more breeder production that way?

That's close to exactly what I would like to do, keep the breeders in and safe while letting their fry wander out. I just would like to find the number combination that will maximize the production of young. With the one I will first put in the pond, I can start light on the numbers. With the one I put in the pool, I can gradually add more numbers to gauge how they are doing. That one can be my experiment cage and one where I can at least monitor results. I may have to set up a second pool to stock extra minnows that I can add to one or both cages over time. I plan to purchase 1000 of them as that's the unit the nearest hatchery sells them as. I first planned to use that many between the two cages but maybe that's a bad idea and starting off small is the better way to go.

Hopefully my mesh is delivered and waiting for me when I get home from work. It was supposed to be here yesterday. I want to get cracking on this and since we've been drowned by rain this past week in Missouri, the garden is far too soggy to get into and it will give me a good excuse to spend my weekend on this project.

You can get more to spawn in a given area if the males that are protecting the eggs cannot see other close males. i.e. you can get more to breed in a smaller area.

Questions:

I am pondering as to how I am going to build the minnow hotel structures inside the cage.

Would a 9 inch section of 3 diameter corrugated pipe be enough for a minnow to spawn in? I'm wanting to stack as many as I can in the cage but I'd hate to build structures that are worthless to the minnows.

I could also step it up to 12 inch long, 4" diameter pipe. I am also wondering if some minnows will utilize the areas created between the tubes created as I stack and bundle them all together.

Will only one minnow spawn and defend each section of tube or will some of them share space?

Do the minnows lay eggs on the roof or the floor? I am planning on adding some wood sections inbetween some pipe rows. What should be the minimum width of the board I use for that in order to get a minnow to spawn on it?

I know it's a lot of questions and I appreciate all that help to give input on this topic. I still haven't gotten my mesh delivered yet. I hope it gets here soon. We are looking at rain going into the weekend and that will provide me with time and an excuse to get out of the gardens an on to a new and fun project.

I can't say I have heard of anyone using corrugated pipe and I would lean towards smooth pipe or strictly flat surfaces like plastic or wood sheet. Plastic would be lighter and better for your application. I'm not saying the corrugated pipe would not work, but the corrugations may not be the best since they lay the eggs on the "ceiling" of their nesting area and the corrugations may be harder to stick the eggs to in mass.

Rumor has it the parent likes to guard about a 12-18" area. That leads me to believe that two would share a larger space. I have seen several guarding crevices in rock piles that could not have had more than a 4x4" ceiling available for the eggs. Nesting areas may have been at a premium when the FHM population was maxed out in my pond and small crevices were all that was left for the less dominant fish. The individual would run off anything that got within 10 inches of the crevice. They will use just about any hole or ledge that's available. So, I think sections of pipe no less than 6" long would work, but I'd prefer 12 to 18" pieces if you have to use pipe.

If it were me, I'd would use the corrugated cardboard-like plastic that cheap signs are made of along with 1/4" all-thread and nuts/washers to create a tower of 18" square platforms with about 3 inch spacing. Not that I have attempted what your are doing..it's just my thoughts. I used stacked pallets that had close fitting slates with bricks between each pallet for added ceilings and they worked incredible well in my pond.





My final thought would be that any pipe from 3" up would work well, but you are trying to maximize a small space and flats would lend themselves to that goal. You'll produce minnows anyway you go and the advantages of one way over another may be marginal. These FHM, like rabbits, just want to fill the pond with their kind and will find the way to do so given the lack of predators.

QA,

I love that fleet of pallet stacks you have there. I wish I would have done more myself. The rocks are nice too. I put a few pallets in my pond before it filled and a few large brush piles, mostly cedar. I am hoping the minnows will make the most of it. I have some large rocks and lots of gravel and smaller rock.

I may just try to find some free or cheap pallets in town and use wood from those. The idea for corrugated pipe was from some examples I saw on the internet of other people's breeding structure. I thought it may offer more privacy. Thing is though is that I don't want to sink too much money into this. Cheap and easy would be preferable. I have a zillion things I'd like to buy this Spring so if I can go cheap somewhere and still make something function adequately, I'll go that route. If I used pipe, I'd have to figure out how to fasten it or use chicken wire to hold it all in which is a bit befuddling to me. I am thinking about building two or four removable units inside my 4' x 4' x 4' cage while still leaving some room in the center in case I want to run a minnow net through it to pull some out. For the minnow pool (if I ever get that far), my cage will be 4'x4'x2' and likely stick out of the water but I will also have the option of moving that into the pond if I want. For the pool I am going to have to purchase an aerator, pool, and some kind of filter. I am thinking sponge filter that I can run off the aerator. I might also set up a second pool where I can transfer the fry into, let them grow a little and eventually put them into the pond. (more money, uggh)

This will all be one big learning experience but it has my interest up. I am not sure I'll have a pool setup going before the summer heat sets in. I'd hate to be so late that the heat gets high enough to where it restricts breeding. If I can do it and if I am happily surprised with the production, I'll build more cages for the pond as time and money permits.

As esshup menitoned - ""You can get more to spawn in a given area if the males that are protecting the eggs cannot see other close males. i.e. you can get more to breed in a smaller area.""
Pallets will produce more FHM spawning areas if there is an additional divider or wall inside the pallet. Currently pallets have one 2X4 in the middle. An additional 2X4 or similar divider to make the space between the middle and center wall not as wide will allow more spawning of FHM due to their territorial instinct.

In a confined space if you bundle short pipes together this gives FHM males confined spaces to create territories. Example - See page 1 in the Q&A Structure Archive ewest's post dated 29/07/07 time 1:06pm on his pictures 9 and 10 for groups or bundles of pipes.
https://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=92463#Post92463

Wow and Thanks! That's an incredible thread that I'll be all up in like a fresh Philly steak and cheese.. Nice resource and great pics!

In my experience and opinion I think you should reconsider spending a lot of time and effort raising FHM to grow better BG and Bass. Why?
1. For best production you are going to need to feed the FHM which means buying food.

2. And most importantly feeding fish to other fish that eat minnows is a VERY inefficient way to grow your BG and LMB. History and research tells us fish will need to eat about 10 pounds of live food to gain a ONE pound resulting in around a 10:1 conversion. It is much cheaper with less effort to feed the fish a high protein, highly digestible pellet that produces close to a 2:1 or sometimes even close to a 1:1 conversion rate. This means every 1-2 pounds of good quality pellets produces close to 1 pound of fish gain. The pellet conversion ratio of 1:1 lb gain becomes closer if the fish are also able to eat other natural foods in the pond. This also depends on the specie of fish. High quality pellets cost a little more money compared to lower cost pellets but the amount of weigh gain is more and fish waste and water quality loss are measurably LESS and proven with indoor feeding tests for the more expensive fish pellets. It is all about how much of the pellet is digestible to produce fish weight gain and healthy fish. Too many carbohydrates are not good healthy food or fish or humans.

3. Get your pond fish on real good fish food pellets and you will see real good results.

4. Pellet feeding produces lots more bigger fish faster compared to fish living on all natural foods. When producing more fish with pellets, IT BECOMES MORE IMPORTANT TO IMPLEMENT PROPER FISH HARVEST TO MAINTAIN THE QUALITY OF THE FISHERY LONG TERM. Ponds can easily become unhealthy for fish and water quality when feeding too many fish.

5. When feeding pond fish it is very important to understand pond carrying capacity, and proper fish harvest to achieve your goals for the fishery. Different goals require different specific management methods.

Bill, your comments spurred me to think about the best way to use feed in a LMB/BG pond.

Given a set food budget, would it be best to focus on feeding smaller pellets to the BG, or big pellets to the LMB?

Obviously the big pellets will benefit more the LMB that eat them, but not all are feed trained. Most especially wild bred LMB may not come to the feed much. But those that eat big pellets, may ease off on BG predation, helping that population.

The small pellets help the BG that serve as LMB food, of course. Some LMB eat small pellets, too, but most of them end up in BG bellies. One pound of BG is nowhere near as nourishing bass growth as one pound of fish food, but on the other hand BG reproduce in large numbers & utilize natural resources in addition to man made.

What are your thoughts in a pond environment? Does it depend on the carrying capacity?

anthropic - you ask
Your questions are a complex topic to discuss. There are lots of factors involved. Other members can also provide what they have learned on this topic as the thread continues. Here are a few of my initial thoughts.
1. Lots of experience has taught me to first begin with pellet trained fish. Although I have done it both ways of training pond fish to eat pellets while also buying pellet raised fish. The 2nd way is easier and quicker producing the fastest results when someone else pellet trains the stocker fish. Training fish to eat pellets takes time and it is helpful to use the correct training methods which helps a lot for success. Correct methods to train fish to eat pellets is a complete article by itself.

2. If you want some pellet trained fish in a all natural food pond, I suggest that you remove any number of "wild" fish and replace them in equal numbers with pellet trained fish. This relates to carrying capacity. Adding pellet eating fish helps speed the conversion toward a pellet eating fishery. IMPORTANT - The older a pellet raised stocker fish is when purchased,,,,,, the more likely it will remain eating pellets after it is stocked into your pond.

3.. If you are looking to best enhance the whole fish community IMO it is best to feed all the fish species and sizes. This quickly benefits the whole fish community. Usually this means using various sizes of pellet feed for the various sizes of fish. For my small fisheries I use basically one size pellet 1/4". I grind pellets to various sizes for minnows and soften pellets for 3"+ fish. I have learned to soften the pellets so 3" and 16" fish can eat the same soft squeezable pellet. This eliminates buying several sizes of pellets. All my fish seem to grow very well.

4. As far as "What are your thoughts in a pond environment?" Pellet feeding esp using high quality pellets grows more fish pounds and bigger fish faster. This concept is basically the same as raising most all animals for food or your other use. Animal husbandry.

5. There are numerous advantages and disadvantages to a natural fed fishery and a supplemental pellet fed fishery.

6. For best results of a natural and pellet fishery carrying capacity requirements need to be followed for getting or achieving the best results for ones GOALS. Goals have to be realistic based on Mother Nature's Laws.

IMO get feed that is multi sized and feed all. That way you are hedging your risk that either one would be better.
There is a range of feeding from small amount of supplemental to lots of food like aquaculture. So, pond size and goals effect your feeding options - watch your water quality. The more you rely on feeding the more attention you have to pay to management - water quality, carrying capacity, population dynamics and harvest.

Bill, the way I see these kinds of projects, which I very much like by the way, isn't from the perspective of #1 or #2. While it may be true to maximize production would require feeding ... why must one maximize it? What about the case of minnows like FHM and BNM that feed low on the feed chain consuming algae and detritus and thus utilize niches under utilized by BG? They don't need to be fed to do that. In fact, they will probably do a better job of it if not fed. Why not feed a BG a reasonable amount of feed as part of a nutrient budget and let the minnow help to clean up the 77% of the nutrients that are in the manure. Fish are consuming all the time ... mostly on nutrients that are just part of the ponds food web fueled by native nutrients. Minnow fry introductions can utilize this resource, compete with and reduce recruitment of the fry of sport fish, and significantly add to forage with a dry weight nutrient profile that is ~70% protein and packed with all the appropriate amino acids where nothing ... absolutely nothing ... in the minnows is bad for BG and LMB to eat. Minnows will favor the big BG scenario and should probably be replaced with TP for the big LMB scenario.

The feed required to maintain 4 lbs of breeding FHM is minimal while they produce between 1000 and 4000 eggs/pound every day. Of those that hatch ... the fry that infuse the pond ... these fry will add to the food chain by converting nutrient sources that are outside the niche of BG. If a person fed 4% of the weight of the brooder FHM over 100 days we are only talking 4 lbs of feed total with the potential of seeding >400,000 fry.

When a person feeds it converts well and affordably but in a pond that will produce 200 lbs of fish annually and maintain 400 lbs of fish ... all that is free without cost ... without accumulating nutrients ... and so I would say that no feeding is the most efficient way to grow fish and supplementing forage organisms is a way of increasing the production(and maintenance) that is possible when feeding or not. If a pond produces 300 lbs of fish naturally in a season and you feed 60 lbs of feed at direct conversion of 1.5 is the FCR really .176? Or is it just 1.5 where now there are additional nutrients accumulated? To remove the nitrogen in 60 lbs of 42% feed one must harvest 184.61 lbs of BG and/or LMB.

Everyone has an opinion be it correct, wrong, misinterpreted, slanted, or biased. Final results tell the rest of the story.

I am going to go ahead and set up my minnow breeding cage in my pond. I already have the mesh for it and if I end up abandoning it at some point, my cage can be used as a fish holder when it comes time to start. I imagine I'll be giving those in the cage some fish flakes since they will be confined in numbers but for the minnows free swimming in the pond, I am sure there is more than enough naturally available food for them to forage. I may or may not do the pool but the only reason I would is just to see how the pond cage idea may be working. How much it actually makes a difference for the predators in the pond isn't too much of a concern. I want to try it anyways. Worse case scenario is that I have cheap and readily available bait. I have friends that stop by and dig my worms from my compost pile and my soil regenerating pen. They are welcomed to have some free minnows too. I do plan on feeding what fish I can get to eat (haven't seen any eating yet, 2 1/2 weeks since I stocked fingerlings though.) I imagine my pond is incredibly rich right now for the fish that are currently in it.

I for one will be interested in how you think it works out for you. I've got predators in my tiny 1/20th acre forage pond now so just putting in FHM's might not do much good. But what you are doing might just work.

Something you might consider after you get it going is to put a couple of minnow traps in your pond to see if you can capture any of your recruitment minnows. Shallow water, a foot or two deep, is what I have my best luck capturing minnows in a trap. Somewhere in my old forage pond thread I have pictures and a discussion of minnow traps.

In my opinion the Gee's traps are some of the best. As the fish you are trying to capture get a little bigger, a person can enlarge the opening from the standard 1" to 1.5 or so. Be advised though, doing so probably makes it illegal to use in public waters. And captured fish tend to wander back out easier so more frequent content checks are needed.

Edit: Some minnow trap info:

https://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=521163&page=1

About half way down the following page some discussion and pictures of different traps I have used.

https://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=498329&page=2

I have a number of cylindrical bait traps I've made. I should put some in my pond near my dock to see what I may catch. For the minnows, I was thinking of purchasing 1000 of them. (that's what they sell them by in the hatchery nearest to me.) I am guessing that's far too many to put in the breeding cage. I really don't know how many I should put in it. The cage will be 4'x4'x4'. I'm hoping to build it this weekend. If I had a pump and pool set up, I'd put the others in it but I can always dump in the pond what I don't put in the cage. Without the pool though, I won't have any idea how well the cage may be working, and even then, it's likely that the pool cage and pond cage could have different production with different size cages and environment.

I really can't see what harm will come from at least trying it. Sure, having a bunch of tiny newborn minnows freely moving out into the pond may not have much of an effect as far as providing forage but I'm sure something will eat them and at least get some benefit. It won't cost much at all to maintain it after it's started. I can also use the cage for something else so at least building it won't be a waste of money.

I will definitely post progress and results as I come by them.

My idea to start will be to first build the cage as a cube with one or more lids on top. Those who don't I will make a note of it. Once I can obtain some minnows, I will throw them in the cube in the pond. The earliest I can purchase some will be the weekend after next so I probably should see if I can trap some off the dock. I want to put them in the cage and see how much damage they may do to themselves. I bought PVC coated hardware cloth for the mesh. If needed, I can insert rounded corners, but I want to see how the PVC cloth is on them first.

I'll check out those threads you've linked, thanks!

Music to my ears. Observational results must always win out over our opinions.

Bill, all I was saying is that I disagree that it is a waste of his time. If the caged FHM spawn successfully there should be a benefit all other things equal. I doubt that minnows can compete for the feed with BG and LMB anyway. From that perspective neither of the first two conditions apply. First he can't feed them because BG and LMB won't allow them to eat much feed and Second, if the minnows aren't eating feed then they don't make the feed less efficient.

The seeded fry will have to eat natural foods. They will provide some unknown amount of forage depending on the average life span and it may not be a good value in the end if they are all consumed as hatch fry. Is this why you are discouraging it?