Well i know i can plant a seed in promix hp and the "soil" will grow a plant for a month or more. Ive seen it in plant problems many times. Noob thinks his soiless is organic potting soil and doesnt feed, plants turn yellow and he comes here to ask why. The HP after the promix lable means the promix is "teaming with organisms", because its been inoculated with mycorrhizae.
I mean you use the stuff so you should know this. So by definition you are wrong. It may not be able to get a plant to flower well, but it still sustains life easily through a colony of microorganisms. Right?