That bad news. I fight every day against ammonia, tadpoles food very dirty water, that added to the disposal of them. I change half of water daily. I need to mount a water input and output constant. I use to feed tubifex (the problem including many parasites, are collected from the trenches). I also use pacmafood but worse mess. I saw the worms used in USA but are not readily available here, should play myself, I have to read how.
There will be a new possibility.
Greetings from Argentina.