Do small tanks = small fry?

[PineSong]

All other things (water parameters, temperature, plants, light, food) being the same, will fry raised in a small tank grow more slowly than fry in a larger tank?

 

[lefty o]

i have never seen any evidence that would suggest that.

[Atitagain]

Not sure on overall or even if this just seemed like it happed but I think it did 😂 

I had platy fry in a 10G and it didn’t seem like they grew for 6-8 weeks I was waiting for them to get big enough to join the shoal. I finally had to move them thinking I hope their big enough. 60G with 20ish platy then a few other adult fish. It’s been a week and it seems like they tripled their size. I kept looking thinking there’s no way those are the fry! But they were.

[Scapexghost]

No, in fact, raising fry in a smaller tank can be beneficial in some cases. Often fry aren't able to actively hunt for food, and will only eat food that comes directly to them. So, in a smaller tank, the food is more likely to get to them and there is less risk of starvation. 

[PineSong]

On 10/6/2021 at 7:22 AM, Scapexghost said:

No, in fact, raising fry in a smaller tank can be beneficial in some cases. Often fry aren't able to actively hunt for food, and will only eat food that comes directly to them. So, in a smaller tank, the food is more likely to get to them and there is less risk of starvation. 

Yes, I've heard this and it makes sense, especially in the first week or so when fry are quite tiny, or if they are in a tank with high flow or competition for food with adult fish. 

However, these fry are now 2 weeks old, very active and have zero competition for food.  They don't look much larger than they did a week ago, if at all. They do look more mature, just not larger. 

On the other hand, the fry I had born in a 10g have doubled in size in the first week, even with the larger tank, the tank being new without so much infusoria etc. and an adult fish in the tank with them... the parent fish are also larger, though, so kind of comparing apples to oranges.

I just wanted to make sure I'm not stunting my fry by keeping them in the small tank. I can wait for them to grow. I've watched a few youtube videos about raising guppies and I thought I remembered the breeders saying they move the fry to larger tanks to grow, but maybe the reason was crowding/water changes as opposed to size of fry.

 

[CalmedByFish]

On 10/5/2021 at 10:13 PM, Atitagain said:

I had platy fry in a 10G and it didn’t seem like they grew for 6-8 weeks I was waiting for them to get big enough to join the shoal. I finally had to move them thinking I hope their big enough. 60G with 20ish platy then a few other adult fish. It’s been a week and it seems like they tripled their size. I kept looking thinking there’s no way those are the fry! But they were.

Since I currently have platy fry, I'm very interested. Could it be that in the big tank, they have more food or more heat?

[Atitagain]

On 10/6/2021 at 11:43 PM, CalmedByFish said:

Since I currently have platy fry, I'm very interested. Could it be that in the big tank, they have more food or more heat?

The big tank is 3-4 degrees warmer and I really overfeed this tank because along with the platys I have 2 angels then on the bottom 6 peppered Cory and a breeding group (1M 2F) bristlenose plecos. 

[Hobbit]

@PineSong What size tank are they currently in, what are you feeding, and how often are you doing water changes? Like Guppysnail, I have platy fry right now so I’m curious! The larger ones are in a 10g and I’m feeding lots of baby brine. They’ve only been in the tank (as opposed to my outdoor tubs) for about a week. I think they’re growing!

I know @Zenzo attributes the large size of his fish to his frequent water changes. Part of the thought is that there are hormones in the water that stunt fish growth, and the water changes remove those.

[Guppysnail]

Guppies What I have noticed because my boys are grown out in 10g I can have 10-30 at different times. As long as I do water changes daily they grow big. Those times I can’t do daily throughout the grow cycle they remain smaller. Even though parameters stay close to optimal without the changes.  If I have an older batch and mix with a younger batch because I simply run out of room. The younger stay smaller until I move the older. Then they have a growth spurt.  This could also be outcompeted for food though I overfeed heavily and do extra water changes to accommodate the over feeding.  there are also many other factors that could be influencing that I am unaware of. through observation of many many batches this seems to hold true. The ones grown out in a 20l/29/10 boys and girls will all reach the same size eventually for me it’s just a time difference 

Edited October 7, 2021 by Guppysnail

[Zenzo]

There are a few things here that may be attributing to the variance in size. 

- Water temp: I read above that the temp varies between the two tanks. Normally, a warmer tank will speed up metabolism, which may allow the fish to actively look for food for frequently (or fanatically), thus aiding in growth (there many be a biological factor too).

- Water quality: Often times, a smaller tank doesn't have the same water quality. While it is probably not hormones at that stage, things like ammonia and nitrate levels may stunt or slow the growth, even fractionally. Their little bodies may fight a little bit harder to stay healthy rather than expending that energy on growth.

- Feeding: There may be more to graze and nibble on in a larger tank. Not necessarily the actual food that you are adding, but the micro fauna that they will find amongst plants, substrate, algae, etc.

With frequent water changes, a small tank can have advantages (like target feeding like @Scapexghostmentioned), but I think that the key there is to have good water quality. 

[PineSong]

On 10/7/2021 at 8:22 AM, Hobbit said:

@PineSong What size tank are they currently in, what are you feeding, and how often are you doing water changes? Like Guppysnail, I have platy fry right now so I’m curious! The larger ones are in a 10g and I’m feeding lots of baby brine. They’ve only been in the tank (as opposed to my outdoor tubs) for about a week. I think they’re growing!

I know @Zenzo attributes the large size of his fish to his frequent water changes. Part of the thought is that there are hormones in the water that stunt fish growth, and the water changes remove those.

My small fry are in a 5 gallon, they started out on Hikari First Bites 4x a day and  I am now feeding Extreme Krill, Bug Bites, Hikari Micro Pellets 3x a day, and frozen bloodworms some days.

Based on what everyone here is saying; the water changes may be the issue. Even with the overfeeding, 6 or 7 tiny guppy fry in this long-established and plant-packed tank isn't denting the water parameters, so I have not been doing many/big water changes; I've done about half a gallon, twice since they were born. Part of the issue was my gravel vac was just too large to be used with such tiny fry and the fry being so small and also nearly clear, I was really nervous removing water with a cup. I only this past weekend came up with an idea for using airline tubing to get a slow, safer suction so I have done 2 changes in the past 4 days. I can do larger ones and more often, now that I have the airline tubing down.

I am going to do my best to photograph the little buggers and then do larger more frequent water changes and see where that gets me in the next week. Again, I do not mind waiting for them to grow but I don't want to be stunting them. 

Thanks to all who weighed in!

[Torrey]

On 10/7/2021 at 3:34 PM, PineSong said:

My small fry are in a 5 gallon, they started out on Hikari First Bites 4x a day and  I am now feeding Extreme Krill, Bug Bites, Hikari Micro Pellets 3x a day, and frozen bloodworms some days.

Based on what everyone here is saying; the water changes may be the issue. Even with the overfeeding, 6 or 7 tiny guppy fry in this long-established and plant-packed tank isn't denting the water parameters, so I have not been doing many/big water changes; I've done about half a gallon, twice since they were born. Part of the issue was my gravel vac was just too large to be used with such tiny fry and the fry being so small and also nearly clear, I was really nervous removing water with a cup. I only this past weekend came up with an idea for using airline tubing to get a slow, safer suction so I have done 2 changes in the past 4 days. I can do larger ones and more often, now that I have the airline tubing down.

I am going to do my best to photograph the little buggers and then do larger more frequent water changes and see where that gets me in the next week. Again, I do not mind waiting for them to grow but I don't want to be stunting them. 

Thanks to all who weighed in!

The airline tubing, into a white bucket, so you can confirm no fry were sucked up (and if they were, you can easily return them to the tank).

I use airline tubing, also. I have a wire (stainless steel) sieve that I put a coffee filter in, and the sieve fits perfectly in the top of my 5 gallon bucket. All water from my tanks goes through the sieve.

If there are fry present, I add the coffee filter. I check the coffee filter for any snails or fry before I add the coffee filter (and any mulm, etc) to the vermiculture bin. All tank water goes on plants, leaving nothing to accidentally get in the drain to introduce invasive species. 

(PS: this is also a great way to get amphopods out of the amphopod grow tank, with out anything else getting scooped up with the amphopods.)

[Fonske]

I raise small batches of guppy fry (typically about a dozen) in 1g (fry-only) and 5g (with parents).  In both tanks they grow like there is no tomorrow, I have not noticed any difference between the setups. 

[Hobbit]

It might not be the water changes—it may just be the food. Fry will stuff themselves on live food in a way that they just won’t with dry food. Though I’m glad you found a safe way to do water changes! Last night I dreamt that I walked away from the siphon and sucked up all my adult fish, accidentally emptying the whole tank to boot. 😞

[PineSong]

On 10/7/2021 at 11:30 PM, Torrey said:

The airline tubing, into a white bucket, so you can confirm no fry were sucked up (and if they were, you can easily return them to the tank).

I use airline tubing, also. I have a wire (stainless steel) sieve that I put a coffee filter in, and the sieve fits perfectly in the top of my 5 gallon bucket. All water from my tanks goes through the sieve.

If there are fry present, I add the coffee filter. I check the coffee filter for any snails or fry before I add the coffee filter (and any mulm, etc) to the vermiculture bin. All tank water goes on plants, leaving nothing to accidentally get in the drain to introduce invasive species. 

(PS: this is also a great way to get amphopods out of the amphopod grow tank, with out anything else getting scooped up with the amphopods.)

Ooh, I like the addition of the sieve and coffee filter. Thank you! 

[PineSong]

On 10/8/2021 at 9:33 AM, Hobbit said:

It might not be the water changes—it may just be the food. Fry will stuff themselves on live food in a way that they just won’t with dry food. Though I’m glad you found a safe way to do water changes! Last night I dreamt that I walked away from the siphon and sucked up all my adult fish, accidentally emptying the whole tank to boot. 😞

Yeah, I am limited to raising fry without live food, so I will have to settle for the growth rate I get with non-live food. I was wondering whether the "Instant Baby Brine Shrimp" the Co-Op is offering now would be better than the foods I am currently providing. 

[Fonske]

I feed a lot of live and frozen foods, but many of my fishes* grew a lot faster and larger after I added hard-boiled egg yolk to their diet. The effect was so quick and noticeable, I now consider it a must-have food for them.  

*guppy fry and adults,  congo tetras, pearl gourami, leopard bushfish, and angelfish juveniles/adults.

[Guppysnail]

On 10/8/2021 at 10:18 AM, Fonske said:

I feed a lot of live and frozen foods, but many of my fishes* grew a lot faster and larger after I added hard-boiled egg yolk to their diet. The effect was so quick and noticeable, I now consider it a must-have food for them.  

*guppy fry and adults,  congo tetras, pearl gourami, leopard bushfish, and angelfish juveniles/adults.

I have heard the egg yolk thing. I’m curious if it affects your water quality quicker than other foods?  Do you just crumble it in or dry it first etc?  Anything to watch for during feeding this? I would like to try this. 

[lefty o]

ive done the egg yolk thing on occasion. you need to put in very small amounts, or it will foul water quickly. just put it in dry. well usually it sticks to your fingers, so you just dip your fingertip in the tank. depending on how many fish you are feeding, start with large pinhead sized blob of yolk. see if they like it, and you can always add more.

[Fonske]

@Guppysnail I don't see any difference from other foods in my setups (which are mostly small tanks with high stocking levels, high temperatures, strong-ish filtration and large weekly water changes).  I feed egg yolk first time in the morning (because it's a part of my own breakfast, so very convenient). For fry, I rub a tiny (really tiny) amount of yolk between my fingers and rinse in the tank. It makes a cloud of minuscule particles, ideal for fish babies. For adults, I crumble it just a bit. Start with very little and see how fish like it. 

Edited October 8, 2021 by Fonske

[Guppysnail]

On 10/8/2021 at 10:41 AM, Fonske said:

@Guppysnail I don't see any difference from other foods in my setups (which are mostly small tanks with high stocking levels, high temperatures, strong-ish filtration and large weekly water changes).  I feed egg yolk first time in the morning (because it's a part of my own breakfast, so very convenient). For fry, I rub a tiny (really tiny) amount of yolk between my fingers and rinse in the tank. It makes a cloud of minuscule particles, ideal for fish babies. For adults, I crumble it just a bit. Start with very little and see how fish like it. 

Thank you. I’ll have eggs for lunch today and give it a go with my new free swimming CPD. They are so tiny this sounds like the perfect way to add varied nutrition to their diet. 

Edited October 8, 2021 by Guppysnail

[PineSong]

On 10/8/2021 at 10:18 AM, Fonske said:

I feed a lot of live and frozen foods, but many of my fishes* grew a lot faster and larger after I added hard-boiled egg yolk to their diet. The effect was so quick and noticeable, I now consider it a must-have food for them.  

*guppy fry and adults,  congo tetras, pearl gourami, leopard bushfish, and angelfish juveniles/adults.

Thank you for this suggestion. I popped some eggs on the stove when I got home after reading this. I remember egg yolk as fish food from my antique Innes books, and I had thought of it but was afraid to try. Now I will.

[Torrey]

On 10/8/2021 at 7:33 AM, Hobbit said:

It might not be the water changes—it may just be the food. Fry will stuff themselves on live food in a way that they just won’t with dry food. Though I’m glad you found a safe way to do water changes! Last night I dreamt that I walked away from the siphon and sucked up all my adult fish, accidentally emptying the whole tank to boot. 😞

That is not a dream, that is a nightmare {{internet hugs}}

On 10/8/2021 at 4:08 PM, PineSong said:

Thank you for this suggestion. I popped some eggs on the stove when I got home after reading this. I remember egg yolk as fish food from my antique Innes books, and I had thought of it but was afraid to try. Now I will.

It's what I used with the surprise danio fry. I didn't have a comparison tank, so didn't notice the difference in growth. 

 

I need to see if I have old pictures to compare to 🤔

[lefty o]

On 10/8/2021 at 5:08 PM, PineSong said:

Thank you for this suggestion. I popped some eggs on the stove when I got home after reading this. I remember egg yolk as fish food from my antique Innes books, and I had thought of it but was afraid to try. Now I will.

no need to be afraid, just feed tiny amounts.

[PineSong]

On 10/8/2021 at 7:03 PM, lefty o said:

no need to be afraid, just feed tiny amounts.

I did, and all my fish went nuts for it. A feeding frenzy! So glad I tried it.