Hey everyone, I have no idea if this thread is being followed, but I'd figure I'd leave an update at least for the sake of documentation!
First off, the sirens were/ are extremely healthy and relatively easy to raise! My initial estimate of 150 eggs was wildly low. In all, counted 1 by 1, there were just over 1200 eggs, of which probably 90% hatched. I chose to remove all of the eggs from the parents' tank and raised them in a 5 gallon bucket with water from the same tank, and an air stone beneath the egg mass. I only had the skill and resources setup to raise about 150 of them, which I have sold/rehomed in the past years. I still have about 10 that I'm holding onto, at 2 years they are all a little over a foot long, with one outlier who is nearly 20 inches. Several people who I've sold to claim theirs' are 2 foot long now, and it appears food availability/ competition affect their growth rate significantly.
Since this time, I have also managed to breed Siren intermedia and Pseudobranchus striatus! I am working on a website/blog dedicated to caring for and breeding aquatic salamanders where I'm compiling all of my husbamdry information as well as breeding and young-rearing techniques. I will post again here when the site is online!