Declan
Fishaholic
I did think of that, only dilemna (sp?) is in my established uses the juwel internal filter, and in my new one its an elite stingray 5, so unimaginably different..It could easily be that the bettas choked on the bloodworm, ive seen this happen and heard of it happening before as well on numerous types of food.
When you set up a new tank and you've got an existing tank always add some filter media from your existing to the media of your new tank, simply way of avoiding the cycle.
D.