Its been roughly 6 weeks so I thought I post another picture. Scroll up a few postings to see the original picture just after planting.
I actually stopped the test in the corner of the tank and did the entire tank in STS. I've gotten more growth in these 6 weeks than in 6 months with Flourite. Fertilization is with aquariumplants.com root tabs CO2 too. Lighting is 25 umols
There was a Sword in the background of the first pic. I pulled it up and replanted with a smaller one and its now happily sending leaves out.
There's no sign or crumbling or disintegration of the STS. I really like this stuff.