What is the point of substrate? I understand that substrate is used to allow plants something to cling on, but why drop $40 on 9 liters of ada aquasoil? Yes I know that there are nutrients in it for plant roots, but wouldn't regular fert dosing give plants the necessary nutrients? Couldn't a bag of turface drowned in ferts have the capabilities of ada aquasoil? I'm not ranting, but rather extremely confused. There was a thread
where Hoppy had posted a post and I quote
EDIT: I just remembered one test result I have seen. Tom Barr did some testing using two, as I recall, species of aquatic plants, with a few different types of substrates, among which were Lake Tahoe silt, soilmaster select, which is a high CEC material, ADA Aquasoil, S.F. Bay Delta silt, etc. He judged the results, again as I recall, by drying and weighing the plants that grew in the substrates. The soilmaster select was one of the best, Delta silt was one of the best, and Lake Tahoe silt was one of the worst (being largely quartz sand, I would assume). ADA Aquasoil wasn't the best! These results might suggest that high CEC materials do have a significant advantage over pool filter sand.
He clearly says that ada aquasoil did not come out on top but rather soilmaster select, which is now replaced with turface, was one of the best. I'm pretty sure that something that's supposed to be put on a baseball field wouldn't have the key nutrients that an aquatic plant might want. So why did soilmaster select come above ada aquasoil? I myself am not too sure what my question is, but I guess what I'm asking is what's the point of spending so much money on substrate when you could just dose ferts and use turface.