This is the first page that came up when looking up what pH I should be trying to regulate to. It has a lot of generic info, but does seem to cater to really serious frog breeders with talk about running 'algae tanks', and several separate breeding tanks. This page mentions pH, ammonia, nitrates as water quality issues, and has a section on food but that section is mostly about breeding your own algae: http://www.pollywogsworldoffrogs.com/Text-html/tadpole-care.html
From trying to figure out if there was a fungal problem with our tadpoles:
The antifungal that was at the pet store was something called Acriflavine. I tried doing some googling for that and whether it was compatible with frogs and didn't get much useful information. Strangely what is available are mostly scientific studies; what that most likely indicates is that the manufacturers of the supplement are not advertising it for use on tadpoles.
Here's a forum thread where somebody had a problem with established frogs getting white fuzz. The situation also included ammonia and nitrate buildup; one of the comments pins the blame on nitrates and has a link further explaining a "nitrate cycle". http://www.fishlore.com/fishforum/amphibians/117897-dying-frog.html
Not any real info here about fungus, but a very nice story of a tadpole that made it to being a frog, with lots of beautiful forum support for the nice lady that was raising it: http://www.fishlore.com/fishforum/amphibians/152646-froglet-tail.html
I was sent or found a few links for generic tadpole raising hints and tips.
This is a cute little guide with nice pictures. It has instructions for making your own tadpole food by boiling lettuce, something I've seen elsewhere. http://www.wikihow.com/Raise-Tadpoles
This guide is also nice. It seems to show the same level of crowding that we had, but has a lot of cautions to do frequent tank cleaning which is probably where we went wrong. http://www.wikihow.com/Care-for-Common-Frog-Tadpoles
Here's the guide that Beth sent: http://exoticpets.about.com/od/frogsandtoads/a/tadpoles.htm
And some advice that Beth sent about a high-protein diet for later tadpole stages: http://www.mumsnet.com/.../pets/978641-My-Tadpoles-are-dying
