You are right! Honestly, the sheet was a day old at the moment I posted the message on the forum, but there are already 3 people enthusiastically interested in helping me progress further with the data collection, and a lot of changes are being made at the moment.
A lot of the data I initially used was based on claims on certain guides about soil substrates and mixtures often by experts, but the problem with those is that these experts have been working with the same favorite materials for a long time and lack the fresh look on material properties. But now I actually found some decent data from people that have done proper research and including the article above I have found a few more really relevant pieces of research with relatively representative data, which will be an eye-opener for many people here for sure. (just take a look at the water retention, this really surprised me in some cases!) I'll be comparing each and every data I find, and this way it improves the accuracy of the entire sheet ultimately
I'm also thinking of setting up an easy questionnaire to get an image of peoples experiences rather than raw data, which might give more easily understandable insights on the matters.
All input is valued, don't be scared to leave a comment either on the sheet or on this post!
Sincerely,
Bo