# Question- How many fry can I keep



## sarah5775 (Jul 12, 2006)

I currently have about 20-25 fry (balloon molly and guppy) in a five gallon tank

I have another pregnant guppy I'm waiting to give birth in another five gallon tank.

I have a pregnant platy and three other pregnant guppies in my big tank. I was planning on using breeding traps for a few of them.

So I have lots of fry and potential fry. Right now I have a 29 gallon tank with 2 mollies, 10 mollie juvies (1/2 an inch each) 3 platies and 4 guppies. I want to keep three or four of the juvies and add some of the remaining fry to my 29 gallon.

I have pet stores willing to take the extra fry. My question is- how much room do I need for the fry to grow up in? The guy said he'd take them at 3/4 an inch to an inch long. How long does it take balloon mollies and guppies to grow that large?

I have the two five gallon tanks for them to grow up in, and, in addition, I have one half-cycled ten gallon and another I started cycling today.

How many fry can I handle? When should I stop saving them? How many babies can grow to sellable size in the space that I have? I want to save as many as possible, but there has to be a limit at some point, I think.


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## emc7 (Jul 23, 2005)

The more water you change, the faster the fry will grow, and the less likely they are to surpress the growth of smaller fry. I saw a tape on an experiment where many fry were grown in a 2.5 gallon tank. A pitcher of water was replaced every hour all day and the fish grew to full size in extremely close quarters. 

Most livebearers breed at a year old, so you should be about to get them half-grown in a few months. 

Feed well, keep warm, keep the water clean and you maximize growth.

The other tip I can give you is: keep sorting by size. Keep like sizes together even if they are different ages or different species. 

Fish keepers have two limits, territory size, which isn't a problem with fry, and filtration/water quality. If you can't feed the fry enough to grow without the ammonia or nitrite or nitrate getting too high, you have too many fry. You can expand the tank's fish capacity by adding more filters (sponges are good and cheap) and changing more water, more often.


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## sarah5775 (Jul 12, 2006)

Thanks, good advice.

For the five gallon tank with 25-30 fry, I am running two submersible filters (one for a five gallon tank, one for a 2 1/2 gallon tank). If I change 10% of the water every day, will that keep it clean enough?


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## emc7 (Jul 23, 2005)

I think it will be enough when the fry are small, you may need to step it up as they get bigger. This is one of the cases where I like to test water. So you don't have to guess.


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## jones57742 (Sep 8, 2007)

sarah5775 said:


> For the five gallon tank with 25-30 fry, I am running two submersible filters (one for a five gallon tank, one for a 2 1/2 gallon tank). *If I change 10% of the water every day, will that keep it clean enough?*


Not if you want joy.

I have been there, done that and got the Tee shirt.

IMHO, you will need to be doing a minimum of 50% daily WC's (and actually 80% works better) in order to have real joy (I know this to be true for a 5G tank).

The problem which you are going to get into under any WC scenario is this:

The fry should be fed 3 times per day and hence you will have deleterious material (please refer to the BTW which further exacerbates this situation) in the WC water but you will also have a bunch of fry.

My method is way beyond a real kludge.

I first fill a tea pitcher with WC water and then drain the remainder of the WC water through a fine fish net.

I dump the net into the tea pitcher, place the tea pitcher under a kitchen light, refill the tank and by the time the tank is refilled the deleterious material in the tea pitcher will have substantially settled out and the fry will be swimming at the top of the water in the tea pitcher when they can be filtered in the net and replaced in the tank. Some will remain in the half full tea pitcher but will easily survive at room temperature until the next day's WC.

Hopefully another member of the Forum knows of a better way to do this!

BTW: My observations indicate that floating plants will increase the health and growth rate of the fry and juvies.




emc7 said:


> Most livebearers *breed at a year old*, so you should be about to get them half-grown in a few months.


em:

As you are aware I am attempting to breed a strain of guppies (for my enjoyment in my main tank [as well as for my angels] and not for commercial purposes) and I wish that I would have kept notes but I believe that I am having 3 month generations.




emc7 said:


> *Feed well*, keep warm, keep the water clean and you maximize growth.


Yes! as per my previous comments and I do slightly overfeed.

Another item is lighting duration.

I have observed that growth rates increase with lighting durations to a maximum of 16 Hours/Day. Lighting durations in excess of 16 Hours/Day appear to be counterproductive.

TR


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## emc7 (Jul 23, 2005)

Sounds likes Jones has been there, go with his advice.


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## sarah5775 (Jul 12, 2006)

Thanks, that is excellent advice, and I will follow it. In fact, I already did- just did my first 50% water change. I"m adding some java moss from my other tank and turning on the light. Thanks!


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## jones57742 (Sep 8, 2007)

emc7 said:


> Sounds likes Jones has been there, go with his advice.


Yep! Many Tee shirts.

Really makes you feel like s...t when you just know that several of the "big eyes" are missing (from newborn to like 5 days old their eyes appear as big as their bodies).

What is odd is that I have no problem in dropping young cull juvies into my main tank for my angels.

TR


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## Manthalynn (Aug 23, 2008)

Just another observation: I had about 25 fry on 11/8. I isolated them in my 5 gal for a few weeks. Then I moved some around in the following manner:

5gal - left in 6, 84 degrees
10gal - 14, 84 degrees
29gal - 5, 80 degrees

Believe it or not, I don't really think I lost any! (Yeah, jaw dropper there as I think I even left in one adult with them the whole time!)

The ones in the 5 and 10 gals got fed 3-5 times a day with crushed up Baby Bites. The 29gal got its usual once daily feeding of live bearer flake, not crushed up. They all received the same amount of light for the same length of time daily. And they are all planted tanks with other adult fish/invertebrates in them.

6 weeks later, the 5 and 10gal fry are 2-3 times the size of the ones in the 29gal. (Maybe about 3/4 inch long?) So in this case it appears to be the feeding (and possibly temperature) that caused them to grow faster.

I changed the water in the 5gal and 10gal twice as often (2x weekly only). From birth, I noticed 3 total with kinky tails, but I can't find those ones anymore (I last saw them about 3 weeks ago). Count wise I haven't lost any, but I don't think that's something they outgrow, so I'm guessing I just didn't count correctly. I'm looking forward to trading these juvies in for some more plants in another month. 

It's been fun to watch them grow.


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## madamsuz (Dec 20, 2008)

i have a thread opends thast asking baout this question

i have only changed water or a percentage of the water once a week

what dose so many water changed do to make them grow???


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## jones57742 (Sep 8, 2007)

madamsuz said:


> i have a thread opends thast asking baout this question
> 
> i have only changed water or a percentage of the water once a week
> 
> what dose so many water changed do to make them grow???


mm:

Just curious: when you right click in the input text box is one of the options "Check Spelling"? and are you using Internet Explorer?

25% weekly WC's should produce typical fry growth.

*Absolute pristine water conditions. * Per Sam's experimenting frequent feeding (which implies that overfeeding will be evident) yields significant growth but also yields poor water quality unless mitigated and the filtration typically associated with small growout tanks will not produce these conditions: hence the frequent WC's.

TR


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