Question: Daphnia disappearing/Running out/Dying - What next?

I'm currently attempting to keep around 40 small larve fed, I'm aware that there's bound to be unexpected casualties and such so I'm trying to feed as many as I can afford to. I've already lost a fair few as it's my big ones first batch.

Before the little guys hatched I set up some daphnia in a small fish bowl, I went for a 'neglectful' approach for the daphnia that I'd seen suggested on here. I put in some water from my adults tank and also I put two of these algae-eating-fish feeding pellets and left those to dissolve in the tank in the hopes to start something up quicker.

I also put a pinch of fish food in the top each day which I'd seen as a suggestion to get the algae going. Now within a few days this tank was pure green, the sides were thick with algae, which I thought was a good sign. There were hundreds of daphnia thriving in there once they went in from what I could see.

After using them for a few feeds however, after about a week, there seemed to be little to none left. I found these weird worms (kind of like bloodworms with pincers?) That had hatched out of some kind of weird clear carapace (?) thing. I came to the conclusion that they may have been laid in there by a bug that had come in through the window gone on some sort of feeding rampage and ate a load of them?

I just wanted to see if that may have been the reason or if I could have given better conditions?

I got them from here live daphnia fish food x 7 150ml bags great source of nutrition a weeks supply | eBay 7 150ml bags. I'm not suggesting that these are bad suppliers, I'm just wondering if that is enough to get at once?

The little ones are eating them fine but they're 12 days hatched and still really small so I'm not sure I'm giving them enough each or if it's the best food for them. I've ordered a small sample of baby brine shrimp to see if the supplier I got them from on ebay send ones that would be the right size for them, as with daphnia it's usually hard to pick out the small ones and they run out quite quickly...

Sorry for going into so much detail but from what I see on this forum people who respond usually have a lot of questions anyway! Thanks for taking the time to read!

Take a brine shrimp net and a glass jar to a local pond or lake and sweep the net along the edge of the water. Dip the net into the jar and look for pond infusia. If you see some keep netting. If not try a different area along the shore. That is how I raise my larvae. I can't be bothered hatching brine shrimp or like risking transfering salt to my larvae tanks. If you need a lot bring a bucket and pour the jar contents into the bucket. Keep checking the jar to make sure you are still collecting food items. Make sure you are not collecting any dangerous bug larvae too.

Probably gnat or midge larvae, I have swarms of flies in every water collection point in my garden right now - water butt, bucket, old pots etc. And I had damsel fly larvae hitch a ride into my tank too!

Once you get rid of the invading larvae you should be able to raise your daphnia without issues, but if your original source can from a pond you may be getting unwanted beasties with the daphnia. If you need to start again get a proper daphnia starter culture, easy to find on ebay.

BBS are really easy to hatch yourself - you need a 2L coke bottle, an air pump and some sea salt (and BS eggs). I set mine up in a seed propagator with a freezer cool bag over the top to keep it all warm.

Yep I've just googled midge larve and they looked exactly like that! I don't think they came in the daphnia when I bought them however, is it possible they got in through the open window? I've moved them away from there now. I'm far too worried about giving them nasties to go fishing for wild daphnia, also working full time doesn't help that option!

My latest delivery was late so I tried the chopped frozen bloodworm for about half an hour yesterday and no luck at all! Dropped it above them, swished it round in the water and no interest at all. I guess they're just not ready for that yet. Hopefully within a week or so I'll be able to get them to take that as I'm not having much luck with daphnia!

I've had a sample of bbs delivered today and I'm going to try them with that as soon as I get home from work and see how that goes! I also have some more daphnia on the way just incase.... suppose I'm just going to have to face the facts that I'll have to spend more money on them if I want to raise them!

Thanks for the help