Fry Crisis :(

[Alienchick017]

I have a spawn log but decided to post a new thread hoping more people will see this and can give me advise. My fry/juvies are almost 9 weeks old and up until now I haven't had any die offs other than when they were only a few weeks old here and there but all of a sudden they have started dying 1-2 a day for the last few days. Its mostly been smaller ones so at first I thought maybe it was due to them being runts and the larger ones bullying them but yesterday I had one of the larger ones acting very lethargic and wouldn't eat so I jarred her and she had died by the next day and today I found a large one dead in the tank. All of them are spending a lot of time either at the top or laying on the bottom and I don't have a clue what to do.
There are about 45-50 fry in a 10 gallon that gets 50%-100% water changes every day. The temp stays around 85f but sometimes the light makes it go up to almost 90. I feed them frozen blood worms, frozen brine shrimp and Hikari tropical micro pellets(which I'm worried may be the problem). I checked the Ammonia and it was up(maybe from the dead fish?) Any advise would be greatly appreciated.. I've worked so hard raising these babies and I'd hate to loose them all now :(

[Fabian]

Try lowering the temperature.I don't think you need 100% water change everyday,50% sounds good.

[jeffegg2]

Is the tank filtered? Is the water you are using aged?

If the tank is not filtered then that could be the cause of the ammonia spiking.

If you are really doing 100% a day water changes, then how do you condition the water? Is the water pre-heated to the temperature of the old?

[Alienchick017]

I do 100% most of the time because it isn't filtered. I normally do filter less cycling on my tanks and was worried that wouldn't work with so many fry so I have a back up DIY sponge filter that I will add to the tank. I also noticed that some of the fry will suddenly dart around the tank kinda bouncing off of the walls and plants, and now only about 5 of them are eating. Do you think it could be a bacterial infection? I recently had a male get dropsy and die and I'm worried that whatever infection he had could have spread to this tank.
I treat the water with conditioner and it is the same temp when I put it in.

[LittleBettaFish]

If they are flashing or scratching themselves it could be either irritation from ammonia exposure or they could have something like ich or velvet. If you get a flashlight, are they big enough that you can see anything on them?

[jeffegg2]

That many fry in an unfiltered 10 gal you really should be running a sponge filter and doing water changes.

10 bucks for a good sponge filter.

Jeff.

[Alienchick017]

I have a sponge filter already but I was trying to go filter less with this one like with my others(I did make sure to be prepared just in case). Up until now I have had no problems with ammonia at all when I test it weekly. Also I wasn't expecting there to be so many considering that it is my 1st time.
There is nothing different about them physically with a flash light on them and after doing 2 50% water changes today they are doing MUCH better and are eating again other than a couple of the smaller/weaker ones. I definitely think the ammonia spike was the cause. Thanks for the advise.

[jeffegg2]

I'm not understanding the advantage of "Filter less". When the fry are newborn until the first week or so sure, but after that you should have a sponge filter running. Ammonia is very toxic.

Glad to see your water changes are working

Jeff.

[EvilVOG]

What Jeff said. The "beneficial bacteria" that helps keep water in check lives in the sponge material of the filter.

Also that's alot of fish in a 10 gallon. When my spawn was around this age i moved 65% of the largest of the spawn to a 30 gallon tub, and left the remaining 35% in the 10 gallon. But i was also breeding giants, yours might not be there yet.