Why are my betta fry dying?

So about two weekd ago me bettas spawn and produce about 30 eggs. The fry hatch and all went oaky until they were freeswimming. Then they started to die. I found about 4-5 dead ones a day! I feed microworms and bbs. Is this bad water quality or bad genes? (if there exist such a thing?) I bred this male before with another female and they also had 30 fry who started to die. Only three survive and one have a little problems swimming. Genes perhaps?
Thanks

 

@Rooivlerkie, the weather we have been having would have caused some temp fluctuations in your tank. it could be that, I am not really qualified to answer this question. Maybe @HennieRoux can help

 

Hi, is your tank closed on top, or open?

 

Yes the tank`s top is covered. The reason why i think it may be genetics is, because there where other posts in which members said some of their fry have swimming problems, don`t grow fast etc...

 

If the top is covered, no draughts, them yes, maybe bad genes.

 

Difficult to say, to ways to check, breed them again or swop either male or female. Remember that the salt in bbs will couse swim bladder problems if you over feed, so if they didnt have the problem when they where born then chances are the bbs is causing it.

 

I don`t think I had overfed. The reason why I think it may be bad genes I bred this male before and then only 3 fry survived. I`ll try and breed this female with another white male and then let you know. So far I have only 5 fry that survived.

 

could this also be the cause of an old male???

 

I doubt age will effect the genes

 

Well wheter its bad genes or not I have 4 fry left. I hope these surivive. They are still small but I can see a blueish sheen on them. Feed them BBS (And they eat it!) and microworms. Anything else I can do to make them grow fast?
Thanks

 

Water changes good filtration

 

thanks

 

some people say they feed their betta fry egg yolk. Does that work?

 

You can feed them egg yolk but this will contribute to the waste levels in your tank raising the ammonia and nitrate levels in your tank if uneaten food is left in the tank for to long. Stick to the bbs and micro worms and water changes lots and lots of water changes, the water quality is the most important thing

 

Definitely water changes is the most important.
Remember, when you feed these little guys, most of the food falls to the bottom of the tank.
Becuase you can't use any filteration yet, they become toxic really quick.
The only way to remove bulk of the decaying food, is with water changes.

 

Read sometime ago that for gourami-fry aso it's important to use an airstone. Otherwise they couldn't "break" the watersurface and they'd drown.

 

That is why a sponge filter is a requirement in all breeding tanks which is also fry safe, will increase oxygen levels in the water and decrease the amount of film that build up on the water surface. Though most labyrinth fish fry only start taking in oxygen from the surface of the water at around 2 weeks to a month old when the labyrinth is fully formed if im correct (can't remember exactly when):notrust: