Unfortunately, instant algae is not alive. You can enrich the rots with it, grow the rots with it, use it in the larval tank to keep the rots nutritious, but....
The great advantage of live phyto is that when you add it to the larval tank, it doesn't die until it's consumed by the rots, so it keeps the rots nutritious, and helps the larvae find food like instant algae, but the difference is that it doesn't rot and foul the water, and it
helps to absorb ammonia!!!!!!
I've been using instant algae to grow and enrich the rots, but keeping a culture of phyto alive in addition to add to the larval tank.
Unfortunately, you cannot grow a culture from instant algae. It's dead. I've heard that it is very difficult to culture even DT's anymore. Best to find a friend with a live culture or order some. Then culture your own.
Good luck with those eggs, Mike! They will probably hatch tonight! Happy New Year!