I've used carib sea eco complete, keep in mind it is a live sand and as such once the minerals and nutrients in the soil have been exhausted the solo will become dead and need to be replaced, this generally takes between a year or two.
Personally I would recommend an inert and. Play sand works well is inexpensive and can be found at most hardware stores. Personally I use black diamond blasting sand. It's inert it's black it's inexpensive it's great for staying plants roots and it won't harm fish including bottom dwellers though if one is planning on having corydora most would recommend play sand over black diamond blasting sand as it a little more fine though I've never had any problems with black diamond sand or read about any problems with black diamond sand for corydoras. If those two don't sit you one could try pool filter sand, it's a little larger grain size and comes in beige it's also inexpensive great for aerating roots but beware it also contains silicon that can cause algae.
Keep in mind as all 3 of these same are inert all three will need to be supplemented with fertilizers.
Most people accomplish this through root tabs, the leading brand is flourish root tabs. They cost about 10 bucks for 10 tabs follow the directions on the pack they need to be replaced about every couple months depending on plant load.
Those are the 3 that are the least expensive and easiest to care for and won't need to be replaced after a year or so.
I've tried all the fancy store bought substrates and the ones that have worked best for me are play sand and black blasting sand. Good luck
I just thought plants might not actually stay in the sand? But I guess not if you suggested that haha. Thank you by the way!
