Is there a big downside to going with Eco vs Aquasoil? The problem with Aquasoil is the frequent water changes needed for the first month or two, and the amount of maintenance on my (high-tech) tank is what necessitated me leaving the hobby in the first place with a growing family. Even if it's only 4-6 weeks, large water changes a couple times a week or more will be a SIGNIFICANT factor in substrate selection. If Eco Complete will be just fine with water-column dosing only, without a significant decrease in tank health/balance/growth in the future, I would be happy with it. I noted that Barr used Onyx sand for his testing purposes.