Reflections On Some Live Foods I Have Known

[memorywrangler]

Two years ago, I returned to fish keeping after a 30 year hiatus, and quickly became enamored with the idea of raising live foods.  I had daydreamed about them I was 12 or 13 and read about exotica like “daphnia” and “scuds”.  I had no idea how to acquire, much less raise, them.  Now, with the internet and a grown up’s pay check, those and many other live foods are within reach.

In the past two years I have tried my hand at a bunch of different live foods.  At times I’ve been more excited about the live foods than the fish I was feeding them too and have frequently found myself with more live food that fish to feed them to.  I even bought a microscope (ok, maybe two microscopes) so I could see what was going on.

I thought I would share my experience, impressions, and especially useful tips I found or discovered along the way.

Here they are in roughly the order I tried them:

Vinegar Eels

These were my first.  So easy.  Apple cider vinegar and apples in a bottle on the shelf.

Tip: The method usually given for harvesting them (with the filter floss and fresh water in narrow-mouthed bottle) is overly complex.  I just sucked some vinegar out into a brine shrimp net, rinsed them a bit, and dumped them in the tank.

Infusoria

Infusoria are a great science project:  It’s good fun watching a jar of weak vegetable broth process from clear to cloudy with bacteria to clear with tiny paramecium motes of food swimming around.   I had great fun looking at infusoria under my microscope.

But it can be an unpredictable and smelly hassle, too.  Sometimes the cultures go bad, and it can be hard to start cultures at the right moment so you have infusoria ready when your fry need it.

Still, it’s cheap and readily available.

Tip:  Don't use cabbage or brussels sprouts to start your infusoria, or it will be extra stinky.

Moina — Round 1

These guys caught my eye from the start, since they are small, I keep mostly small fish, and you can order the eggs from Geenwater Farms on Amazon.  The eggs worked, and pretty soon I had a nice little colony of them growing in two 2.5-gallon drink dispensers.

It was a hit-and-miss process that you can read about here: https://forum.aquariumcoop.com/topic/31271-any-ideas-to-refine-this-moinadaphnia-culture-approach/

I tried all sort of things:

1. Co-culturing with snails and/or black worms.
2. Feeding the snails vegetable and watermelon scraps.
3. Growing aquaponic strawberries with them.
4. Adding corn husks to increase surface area which some articles suggested would be useful.
5. Blasting them with grow lights 20 hours a day.

I also tried and tried to grow some green water, but to no avail.  Well, almost no avail:  I could  grow green water (https://forum.aquariumcoop.com/topic/29405-crashed-moina-cultures-converted-to-accidental-green-water/), but my moina wouldn’t eat whatever variety of algae it was.

In the end, it worked ok, but the cultures would crash every 6 weeks or so, which was annoying.  Eventually, the drink dispensers developed cracks, I got frustrated, and I gave up (for a time…).

Black Worms

I tried black worms at about the same time as moina — first keeping them in a bowl with an air stone and then graduating to bigger and bigger containers.  These would crash on me too — all of sudden they would all just disappear.  I thought maybe they had escaped en-masse, but I never found any evidence of that.  They just vanished.  I did some experiments about how to prevent this: https://forum.aquariumcoop.com/topic/31877-suggestions-including-salt-to-prevent-blackworm-culture-crashes/.

My main conclusion is that building a self-sustaining culture of black worms is pretty hard.  They don’t grow that fast, so you'd need a very large population to generate enough biomass to be self-sustaining.  But it is pretty easy to keep them alive for months (and get some growth).  This has two advantages:  1) I can buy them in larger quantities and 2) I can weather the occasional shortage (There was a really bad/long national shortage last winter).

Most useful resource:  https://forum.aquariumcoop.com/topic/20459-big-bad-blackworm-tower-%E2%80%93-culture-journal/

Tips: Black worms are a widely-used model organism in biology, so there are 100s of research papers written about them.

Unfortunately, very few provide practical advice about raising them.  Instead, most suggest the “paper towel method” which is a completely useless mess.  Just use some gravel and a sponge filter.

Tips: According to one source, black worms often come infested with external parasites, which can cause cultures to crash.  The solution is to soak the worms in a 5-6% salt solution for 20 minutes.  Since I’ve been doing this, I’ve had no more crashes.

Interesting fact:  Black worms eat head down.  So, when you see them sticking out of the substrate, that’s their rear end and gills.

Grindal Worms

I was excited about these — small, supposedly easy to culture, and definitely easy to purchase at my LFS.  The only draw back is that you have to feed them every day, which is a hassle.

I just fed mine cat food, and they’d do great… for a while.  Then something would go wrong:  Mites, fruit flies, mold, nematodes (https://forum.aquariumcoop.com/topic/34442-whats-going-on-in-my-grindal-worm-culture/),  god knowns what, and the culture would fail.  It was super frustrating, because it seemed like it should be so easy.  They just would never multiply enough.   Maybe I harvested too much too early.  Overall, very discouraging, especially since they are great size for many of the fish I keep.

Tip:  My LFS sold cultures with an unsalted (and preferably raw) peanut in it.  It would keep the cultures going if they didn’t feed them for a day or two.  I’ve never seen this tip anywhere else, and it is really helpful.

Paramecium

(photo credit: Wikipedia)

Trying to avoid the hassle of infusoria, I ordered a pure culture of paramecium from a biological supply company.  The idea is paramecium are bigger, more nutritious, and more reliable than infusoria.

I didn’t really find this to be the case.  Mostly I found that it was really hard to keep my paramecium culture from being contaminated and then overrun by other, smaller ciliates (which is basically what’s in infusoria), which sort of defeats the purpose.

Tips: Like black worms, paramecium have been studied ad infinitum by scientists.  Also, like black worms the guidance for culturing them is annoying.  There are two standard methods frequently cited in the scientific literature.  The first involves making a tea of timothy hay (whatever that is).  The second suggests boiling a precise number of wheat berries in a volume of water.

Both of these methods are needlessly fussy.  For the first, I have no idea where to buy timothy hay.  For the second, wheat berries, while cheap on a per-ounce basis, can be hard to find in small quantities.  (Pro tip:  you can buy “farrow” in the bulk food section of grocery stores.  It's just wheat berries).

A better solution is to just throw in a piece of dried, uncooked pasta.

Snails

I had a pea puffer tank for an almost a year and raised rams horn and bladder snails for them.   Nothing could really be easier.  You can feed them anything and they breed like mad.  Mine seemed to like watermelon rind alot.

Scuds (aka Gammarus)

I got the scuds for the pea puffers too.  They take a while to get established because their breeding cycle is about 90 days, but once they are going, they can’t be stopped.  I mean they really can’t be stopped, even if you wanted to stop them.  They are like cockroaches.  Every tank I have is now infested with them.

My conclusion is that scuds are fine if you have enough fish to keep their population in check, but this can take a significant number of fish.  Also, they grow to be pretty large, so you need pretty big fish to keep them under control.   For instance, my nine pea puffers in a 20-long did fine, but when I replaced the puffers with two female bettas and a 6 guppies the scuds got out of hand.

When they are out of control they will eat everything.  For me, they have eaten:

1. The leaves on all my java moss
2. Many of my stem plants (starting at the roots)
3. Some of by Anubis
4. Most of my crypts.
5. Some of my java ferns.
6. A bunch of black worms when they got into my blackwork culture (I have video of this somewhere.  Scuds are savage)
7. Corydoras eggs
8. The breeding colony of assassin snails in one of my tanks.

They also have a big downside compared to moina or daphnia:  They spend most of their time hiding rather than being out one the water column where fish can easily find them.

For complicated life reasons, I’m going to have to shut down all my tanks in a few months, which I think will be my only chance of getting rid of them.  I don’t plan on inviting them back.  They are too hard to control.

Tip:  To harvest I would float a piece of zucchini in the tank.  After a couple hours it would be covered with scuds and I’d lift it out with a brine shrimp net.

Tip:  In the picture you can see a blue scud that showed up in one of my tanks.  Anyone want to selectively breed the next colorful crustacean sensation?  These could be the next cherry shrimp!

Brine Shrimp

I came late to brine shrimp, since the daily grind harvesting and hatching seemed a bit intimidating, and I really wanted moina to work.  But I started breeding fish and moina couldn't keep up.

Overall, it’s very clear why brine shrimp are so popular — They are no less work than all the other kinds of live food (and maybe more), but they are much, much more reliable.

At first, I used those black flying saucer hatcheries, which work great for small quantities.

Then (unwilling to pay for the Ziss) I moved on to a hanging beverage bottle setup.  After some experimentation, I developed what I think is a reasonably nice setup and routine for hatching and harvesting.

Tip:  You can do much better than 3/16 airline tubing to drain your hatchery.  My system uses 3/8" push-fit tubing (like RODI system fittings, but bigger) and a 3D-printed adapter to inject air.  It can drain my 1-liter hatchery in 21 seconds (vs. 63 seconds for the 3/16 airline tubing based system).  Take that, Ziss!

Tip:  There is actually difference between different brands of brine shrimp eggs.  I spent too much time investigating.  You can read about that here:  https://forum.aquariumcoop.com/topic/34636-investigating-differences-in-brine-shrimp-eggs/.

Easy Infusoria

During one of my fish breeding adventures, I was using the some ultra-fine fry food.  I was probably over-feeding because a lot of fell to bottom of the small enclosure I had the fry in.  I noticed that over a couple days the food gave rise to whitish layer on floor of the container.  Out of curiosity, I stuck some under my microscope and found it to be teaming with ciliates and other infusoria-like critters.

So, that’s how I make infusoria now: I sprinkle in some food when the fry are out of their eggs and wait for the white stuff to develop.  The fry can eat the food or the critters.  I found that my Live Food Food (see below) works fine for this too.

Green Water

I did eventually get green water going, but by accident.  I had an idle 20-long grow out tank that I neglected after selling the fry and low-and-behold it turned emerald green.  And this time it was the chlorella -- the good kind of green water. 

I didn't really know what to do with it, though. I used some to start a new moina culture (see below -- it worked fine) and gave a way some at the local fish club, but it doesn't seem to be needed to keep the moina alive, so I ended up dumping most of it.

Moina — Round 2 (w/ Daphnia)

After all of the above frustration, I found myself day-dreaming about moina again.  This time around I bought two, 2.5 gallon aquariums and set them up with heaters, air-lift tubes for circulation, and permanent siphons and with a valve so I could harvest them easily.

 

My eggs had apparently gone stale and wouldn’t hatch, so I ended up buy a mixed culture of moina and daphnia at my local fish club auction.

I’m keeping it simple this time:  No intentional co-culturing — just the moina and the daphnia.  And all I feed them my Live Food Food (recipe below).  Shifting from drink dispensers to aquariums was a huge win since I can actually clearly see what’s going on inside.

So far, so good.  It’s been two months and nothing has crashed.   The moina and daphnia seem to coexist just fine.

The main difference with my approach this time is based on a detail in this excellent article (https://edis.ifas.ufl.edu/publication/FA024) that I had overlooked:  They don’t suggest raising moina as a long-term, self-sustaining culture.   They suggest doing it as a batch culture.  So, this time, I’m expecting them to crash and I’m prepared to strip the tank and start again (which is why I have two cultures going).

By accident, these cultures also produce significant quantities of dero worms and seed shrimp.

Tip: Only feed moina and daphnia when the water is crystal clear.  This prevents fouling.

Tip: Bending acrylic tubing is fun!  The overflows are made from 3/4" acrylic tubing that I heated and bent with a heat gun.  Then I epoxied a drip irrigation valve to one end.  The air valve at the top lets me draw water up to get it into siphon.  Then I can dispense at will!  I also built the airlifts by bending and drilling smaller acrylic tubing.

Live Food Food

Finally, I thought I’d share my recipe for my Live Food Food.  It’s a tweaked version a recipe from Aqarimax Pets ( https://www.aquarimax.com/).  They suggest mixing it with water which is a hassle, but I just keep in a plastic jar with holes drilled in the top and sprinkle it into my tanks.

This is what I feed daphnia, moina, and black worms.  I also use it to create infusoria too.

Ingredients:

• 1 part garbanzo bean flour
• 1 part pea protein
• 1 part brown rice flour
• 2 parts spirulina powder

Instructions:

1. Combine.
2. Mix.
3. Feed.

Notes

The first three ingredients are available in the bulk food or specialty flour section and are super cheap.  Spirulina powder is a little more expensive and available from Amazon.

Here’s a rough nutritional analysis:

• Protein — 40.55%
• Carbohydrate — 40.76%
• Fat — 6.13%
• Fiber — 5.22%

It's roughly similar to some commercial fish foods I looked up.

The Future

As I mentioned above, I have to shut down my all my tanks in a few months, but I should be back in business (scud-free) next summer.

I think my first big project is going to be to build some 5-gallon moina/daphnia cultures into a sump+refugium+auto-feeding setup to simplify the feeding of micro-predators like scarlet badis, indostomus paradoxus, and freshwater pipefish.  I have a forty-gallon tank that would be perfect for it. 

Edited January 2 by memorywrangler
added tip about feeding moinia.

[kammaroon]

Thanks for sharing your experience. Very informative. 

I create quick infusoria by squeezing sponge filter water into a jar and adding a pinch of yeast after seeing this video (his first method):

No smells and works every time. 
 

My grindal worms cultures got infested with mites, same as you. Now I use damp scouring pads for the substrate:

I feed the culture lightly and once every few days. The yields are much lower but I don’t need that much. The worms survived my week of absence over the Christmas period. I rinse out the containers with tap water once a month and haven’t had any problems. 

Edited January 2 by kammaroon
“No smells” rather than “now smells” 😂

[memorywrangler]

On 1/2/2024 at 4:33 AM, kammaroon said:

My grindal worms cultures got infested with mites, same as you. Now I use damp scouring pads for the substrate:

 

This is such an intriguing option!  I tried it, but it never worked.  The worms would just sort of slowly dwindle away.  I think maybe my scrubbers had some kind of cleaning agent on them.  Maybe I'll give it another go later in the year.

[NOLANANO]

@memorywrangler Have you ever read about or tried creating a colony (culture?) of meal worms? I am looking into getting Amazon Puffers and I have read that these are a good food to serve them but I'd rather have my own colony if possible. The issue is that it would either have to be in a box that can fit beneath my tank in the cabinet or be able to survive in my shed because I don't have an area in my house for "gross" looking experiments other than the shed.

 

No disrespect to your work, I think its really cool. My wife just wouldn't agree and would say they are unsightly lol.

Edited January 5 by NOLANANO

[Guppysnail]

On 1/5/2024 at 9:49 AM, NOLANANO said:

@memorywrangler Have you ever read about or tried creating a colony (culture?) of meal worms? I am looking into getting Amazon Puffers and I have read that these are a good food to serve them but I'd rather have my own colony if possible. The issue is that it would either have to be in a box that can fit beneath my tank in the cabinet or be able to survive in my shed because I don't have an area in my house for "gross" looking experiments other than the shed.

 

No disrespect to your work, I think its really cool. My wife just wouldn't agree and would say they are unsightly lol.

I used to do mealworm cultures for my bearded dragon. Super easy. Many methods not a lot of space needed. I also used to culture super worms which are a touch larger and dubia which have a drastically higher protein content. 
 

I did all 3 in small cricket keepers. 
There is more hands on to getting super worms culturing to get started because you need to isolate the worms to get them to pupate.  

[NOLANANO]

I have not tried to research it yet but I assume I can find details online? Any tips for meal worms?

[Guppysnail]

On 1/5/2024 at 11:50 AM, NOLANANO said:

I have not tried to research it yet but I assume I can find details online? Any tips for meal worms?

Keep several small containers.  Starter colony on wheat bran fed veggies kept fresh. As you see them pupate move the pupa to a separate container. Adult beetles tend to eat small larvae and defenseless pupa in my experience.  Once you start to see larvae in the beetle bin move the beetles to a new container. 

[memorywrangler]

On 1/5/2024 at 6:49 AM, NOLANANO said:

No disrespect to your work, I think its really cool. My wife just wouldn't agree and would say they are unsightly lol.

None taken.  I'm under strict orders to keep everything in my man/fish cave 🙂. (Except for one nice display tank in the living room).

[Odd Duck]

For feeding to reptiles, the best nutritional content in the mealworms is only possible when fed only high calcium cricket food that is at least 8% calcium, using this as both bedding and food.  Use a lightly damp paper towel renewed frequently as needed for moisture.  This can be a bit harder to maintain them on, so some keepers still keep the bulk of the culture in cornmeal or bran, feeding high calcium vegetables, then transfer a feedings worth into the high calcium cricket food for at least 48-72 hours before feeding to the reptiles (also dusted with calcium powder {NOT calcium/vitamin combo powder} before feeding).  Fish that are getting mixed diets have less stringent calcium needs but I would still gut load the mealworms on the high calcium cricket food before feeding to fish.

Here’s a link to the recommendations from the guy I consider to be the top reptile nutrition expert in the US.  He has written most of the chapters on reptile nutrition in most of the reptile medicine and surgery veterinary textbooks.

https://www.pethospitalpq.com/how-to-grow-mealworms.pml