How to tell if fry are eating fry powder? How to know how much to feed? - General Fry Feeding Questions

[jwcarlson]

I struggle immensely with fry powder.  I have no idea how much I should be feeding and no clue how to tell if the fry are eating it.  I've got a batch of sterbai corys that started with about 40 eggs, around 30 hatched, and I think I've got around 20 left.  A handful of them have been found sideways or upside down.  Not sure why they died.  The rest look good and are eating baby brine shrimp.  But I put some BBS in on a "whim" because they seemed big enough to eat least chew on them.  They fed on it readily.  Is it possible the others starved?

When you feed fry powder do you cut flow temporarily?  It seems like it disperses quickly when the flow is on.  I mix it with a tiny bit of water and gently squirt it right in the piles of fry and I've not really noticed any sort of obvious eating behavior.  But with BBS they seem to start hunting it immediately.  There might be a handful of them that aren't big enough, but with the absolute mess that fry powder is, I might be better off letting the little ones starve anyway instead of possibly polluting the breeder box.

Does anyone struggle with this?  The powder I'm just feeding a couple of times a day and I don't feel like it's all that much.  I do think that I lost the majority of a CPD batch some time ago to overfeeding fry powder.  Anyone else struggle with this?  Do you notice little green bellies when you're feeding the powder?  How soon after feeding should I suck the extra out?

I know that this depends a lot on the fry size, but can you substitute SF strain BBS for fry powder for a bit in lieu of the powder for some species?

I'm sure I've got other questions, but that's all for now.  

[TOtrees]

I do have the same problems, with the same species. I raise them in a hang on breeder box attached to the same tank as the parents (eggs are hatched in a tumbler). I see pretty high mortality in the first 2-4 weeks. I get best results when i keep the bottom of the fry box immaculately obsessively clean. I've tried adding moss and even bits of almond leaf, and it doesn't improve it. So i put in a piece of small cpvc with an elbow on one end (so it doesn't roll) for shelter, and that's it that's all. A small flat rock would also work. I feed the tiniest amount of fry food a few times per day. I'll often add a baby ramshorn just to try and stay ahead of uneaten food between cleanings. 

The amount of food I add is so small that I don't need to suspend it in water before adding it. I took a thin bamboo skewer, literally split it down the middle and use that as a scoop for my powder. Maybe only 1/4" at the end of the skewer has powder on it, and it's not even piled high. I don't turn off the water or bubbles. 

Since the babies are such slow feeders, I continue to feed the fry food even after they start taking live bbs. You might also try frozen bbs, they come in a wee bit smaller than the live. And they settle to the bottom when added. Again, tiniest of tiny amounts. If you leave the water flowing, the food/bbs will collect in the same places the babies do. 

I've actually had to mod my breeder box to get a line of bubbles coming up from the bottom right at the outflow, bc the babies are small enough to make it through the screen there and back into the tank where they are instantly eaten. The line of bubbles under the screen prevents them from finding the openings. I drilled the bottom of the fry box, and craxy glued on a check valve with one end protruding into the tank. No stone just the plastic connector in the valve. On top of that, I drape a piece of fine mesh over the outflow screen for added prevention. The mesh is cut from an old media bag, sized to the width of the screen. 

[jwcarlson]

I have a few pond snails in the box (to keep it cleaner).  And I clean the bottom nightly.  Plus spot cleaning if I see anything out of whack.

I wonder, though, how much my high pH/hard water might effect the viability of fry.  Mainly that the water is more conducive to bacterial growth compared to something softer and more acidic.  I've thought about running a UV sterilizer, but also want to try a more dedicated fry rearing setup.  Maybe that first and then think about UV.

This is outside of the scope of this thread, but I collected a bunch more sterbai eggs a couple of days ago and the VAST majority turned white.  Not sure if it's fungus, they don't look fuzzy.  Just white inside, so maybe just infertile?  What worries me is this is exactly what happened with CPDs.  The first spawn was good and the second and every other time after has been a total failure.  I think of the ~50 eggs maybe 10 of them seem to be developing still.  I cleaned out the infertile ones today.  And yes, I use methylene blue.

[TOtrees]

Also, a really useful cleaning tool i made is a flat-ended vac tube. Not sure if you can get it, but the 1/8" rigid clear tubing is a must for this. It attaches to standard airline tubing. Take a 6" or so section of the rigid tubing, and gently heat up one end to make it malleable. Use a small paring knife (thin blade, pointy tip) to widen and spread and flatten but not split one end so the opening is like a horizontal line, not a circle. It should end up working like those old school pool vacuums, where the flat part flares out and maximizes contact with the floor, and even does a bit of scraping as you go. I'll take some closeups of mine when I get home. 

[jwcarlson]

On 11/27/2023 at 12:26 PM, TOtrees said:

Also, a really useful cleaning tool i made is a flat-ended vac tube. Not sure if you can get it, but the 1/8" rigid clear tubing is a must for this. It attaches to standard airline tubing. Take a 6" or so section of the rigid tubing, and gently heat up one end to make it malleable. Use a small paring knife (thin blade, pointy tip) to widen and spread and flatten but not split one end so the opening is like a horizontal line, not a circle. It should end up working like those old school pool vacuums, where the flat part flares out and maximizes contact with the floor, and even does a bit of scraping as you go. I'll take some closeups of mine when I get home. 

That makes sense.  I have a bigger tube that works well, but the suction is pretty small and can be tough to avoid the fry.  But I'm going into a bucket so they're easy enough to get out if I get them accidentally.  I have the 3/16" rigid tube as well.  The one I currently use, the standard air hose goes *inside* the ID of the tube, so it must be 1/4".  It's what I had and it works as long as I am careful.  I pinch the air line to regulate flow a bit.

[TOtrees]

On 11/27/2023 at 1:26 PM, jwcarlson said:

This is outside of the scope of this thread, but I collected a bunch more sterbai eggs a couple of days ago and the VAST majority turned white.  Not sure if it's fungus, they don't look fuzzy.  Just white inside, so maybe just infertile?  What worries me is this is exactly what happened with CPDs.  The first spawn was good and the second and every other time after has been a total failure.  I think of the ~50 eggs maybe 10 of them seem to be developing still.  I cleaned out the infertile ones today.  And yes, I use methylene blue.

I use a tumbler inside the main tank, and remove it daily for a 15 min bath with 2mL of 3% hydroxide added to the tumbler. The tumbler is Ziss ZET-55, which holds around 1 cup or 250ml water. At the end of the 15 mins, I pour off the treated water into the main tank, refill with tank water, and reinstall in the tank. 

[jwcarlson]

Does that keep the eggs clean?  I had the air stone in this batch down pretty low and didn't really think about it until yesterday to turn it up when I saw quite a few were white.  Maybe I suffocated them. 😞  I can see the advantage to changing water in the egg container, I don't know where all the "gunk" in my breeder box comes from with the eggs.  I fill it with tank water, it seems relatively clean, but some scum stuff is always all over everything by the time the eggs get close to hatching.  I'll have to look at a tumbler.  I have zero luck getting my cory eggs to stick even if I pull them off the mop a couple minutes after they are laid.  

 

Thanks for your thoughts!

[Guppysnail]

I mix sera in water and squirt in the water near the fry. I never squirt on the fry. I feel it’s fine enough to clog the gills. It diereses everywhere but their sifting action that small works much like pleco skimming every surface. If they are not free swimming enough to find it in the hatch container they are too young to eat it.  
 

Is your fry box floating or external flow through or a tank?  External flow through I must use a small heater. My house is too cold and the slow flow rate allows the box to drop to an unacceptable temperature. 
 

I turn off air or flow only long enough for the powder to settle to the bottom so maybe 3-4 minutes max. 

[Guppysnail]

BTW if you use a good strong magnifying glass you can indeed see their belly expand and a slight green tint. Don’t get this wet though  I destroyed the first white  one I had  like this, water gets between the lenses  

[jwcarlson]

It's external for now, @Guppysnail.  We're at a weird time of year when my basement is warmer than the rest of the house which is currently probably in the upper 50s.  We're trying to make it through November without turning on the heater (we're in Iowa).  Basement is closer to 70.  

I'm currently working on a better fry system, in part because I feel like I have little control over the environment of the fry when I'm connected to a community tank for instance.

I certainly squirted it right on them.  And I won't lie, I thought that could certainly be an issue.  I didn't notice any issues directly, but it's impossible to know.  

I do still think I'm feeding too much, I will have to internalize that.  The BBS I am sure can eventually cause an issue.  But I don't see much waste at all other than some of the BBS might still be left over.

[Guppysnail]

I use these to keep the temp up in external flow through boxes. I also do a manual water change using airline with a piece of sponge over the intake after feeding and let the tank flow fill the box back up. I find the fry boxes still allow for ammonia and nitrite to show when I over feed. 
Im going to do some photos quick for you on how much I feed both powder and live bbs. Hopefully that will help you out. 

[Guppysnail]

My GBR were the most recent. I’ll share the video so you get perspective. Roughly 100 fry in the large fluval hang outside. I hung it inside and opted for manual water changes to ensure 82 degrees in my freezing 68 house 🤣

As soon as they are large enough for bbs they have outgrown the sera micron so I switch to hikari first bites.

Sera

I feed 4ml of this concentration every 2-3 hours and throw the rest out, it turns high concentration ammonia if I try to hold for next feeding. 

 

First bites-same procedure,same 4 ml

For both powdered foods I vacuum 30 minutes after second feeding using this old air tube from a ugf or airline zip tied to a chop stick and my magnifying glass (old eyes) I vacuum into a shallow bright container in case I accidentally slurp a fry. The fungus that begins to grow on the food will attack fry especially the latter hatched  

BBS- I ALWAYS rinse for fry. 2 ml at this concentration  I wait for all to be consumed and if any fry do not have happy orange bellies I feed more .5 ml at a time until they are all full bellies  

I used to feed double or triple this losing fry until I got the magnifying glass  I can see the bellies with it and realized just how severely I was over feeding.  

a week or so old 

 

[jwcarlson]

That certainly helps put things in perspective, thank you!  I've got a few fry powders that (I think) increase in size.  Or otherwise I bought multiples of the same thing.  I've got to scale it to the size of the spawn, of course.

When you overfed BBS, what do you notice?  Greater mortality?  Any symptoms?  Is just seeing a belly with any orange in it "good enough"?  

Just trying to get a feel, I guess I could take a video and maybe it would be really obvious to someone else.

 

Regarding the heater in the external box.  I don't mind the idea, but frankly, I'm tired of dealing with hose and cords.  I've got a small submersible pump in my sterbai spawning setup and that stinking cord is in the way so often.  😄  I've actually been doing quite a bit of work in my "fish room" the last month or so.  I've built two bedrooms in a previously unfinished basement and I'm working on getting my fish room area better setup.  Including a better fry rearing situation as I'm tired of crouching or sitting on the floor to observe fry.  I'm only 39, but I'm old enough that I don't want to do that.

[Guppysnail]

On 11/27/2023 at 4:07 PM, jwcarlson said:

When you overfed BBS, what do you notice?  Greater mortality?  Any symptoms?  Is just seeing a belly with any orange in it "good enough"?  

The only fry I had expire from overeating bbs are guppies 🐷 

The rest breathe heavy and head to the surface. The mortality comes from the excess bbs dying and fouling water. They drop to the floor as they start to expire and hide in corners so I don’t always see excess floating in the water. I’m certain feeding to the point they struggle is unhealthy and may have long term impact. 
 

[Tlindsey]

How old are the fry did you remove the fry from the parents. 

I learned that fry will feed off slime coat of the parents. 

 

 

Edited November 28, 2023 by Tlindsey

[jwcarlson]

On 11/27/2023 at 5:59 PM, Tlindsey said:

How old are the fry did you remove the fry from the parents. 

I learned that fry will feed off slime coat of the parents. 

 

 

Discus fry will feed off the parents slime.  I am unsure if any other fish do, but I don't think any other do.  These are sterbai corydoras and they're just a handful of days old.  Yes removed from the parents as eggs and hatched in an internal breeder box then external when they hatched.

[Tlindsey]

On 11/27/2023 at 7:26 PM, jwcarlson said:

These are sterbai corydoras

Oh I do apologize thought you were referring to Discus. 

[jwcarlson]

On 11/27/2023 at 6:30 PM, Tlindsey said:

Oh I do apologize thought you were referring to Discus. 

No problem! 🙂  I'm such a trainwreck with other fry I can't imagine what discus would be like.

[TOtrees]

Just adding a few pics of some of the stuff I described above...

This is my vac device...

Here's the mods to the hang on box...

And here's how much i feed the fry in the box (say 10-20 or less)...

[jwcarlson]

I might have to do one of those little siphon things.  That looks handy.  

The overflow on the box, I put a fine sponge cut to fit in there and it seems to work well.  The little gate that comes with it is a joke.  There are full grown fish that can swim through it easily.

[TOtrees]

On 11/28/2023 at 4:54 PM, jwcarlson said:

The little gate that comes with it is a joke.

And so prone to loss. There's a good 3d printer project if ever there was one. 

[jwcarlson]

The gate would actually be pretty good if it was somehow farther toward the tank and you could just use it as a backing for a small sponge.  

[TOtrees]

On 11/29/2023 at 8:52 AM, jwcarlson said:

The gate would actually be pretty good if it was somehow farther toward the tank and you could just use it as a backing for a small sponge.  

In the pics I posted above, with the mesh draped over the gate, you can't see it but the gate actually has a very thin slice of coarse-ish foam glued to it on the tank side. I've found those gates collect debris quite easily, and if it's too much it will back up and overflow. So if you use fine foam, which would seem to make sense for keeping fry in, it clogs pretty quick and causes other issues. If you rinse it daily that would likely solve the issue. 

Once the fry get a bit bigger, it's not an issue bc the gate works as intended. It's just for the first week they get through the factory setup. 

It goes without saying the Dean's fry racks (tm) are a far better solution, but if you only have a batch of eggs every now and then it's a touch setup to get off the ground. 

[jwcarlson]

I usually get a couple of days before I get concerned with the sponge backing up, but in almost every circumstance I'm doing a bottom vac in the box anyway, so it takes a couple seconds to squeeze the sponge out.  

I'm curious how often Dean needs to clean the trays in his system.  I guess I'll see what it's like when I get mine up and running.  I should have fry in my copy of his system within the next couple of days.