Creating a live plant-friendly substrate: suggestions needed

[EpaPuff]

I wasn't aware of the risks associated with Seachem Flourish Excel, thanks for sharing. I've come across some horror stories about people overdosing their tanks and watching their plants disintegrate. I'm extremely cautious when it comes to dosing, my fish are my top priority. I recall reading a thread where someone experimented with gradually increasing the dosage of a similar product, starting with a minimal amount and tripling the recommended dose over a few months. The focus was on the plants' reaction, but what struck me was the lack of discussion about the potential impact on the fish. It's crucial to remember that fish, like plants, need time to acclimatize to changes in their environment.

[EpaPuff]

I'm revamping my 125-gallon tank to convert it into a planted setup, and I'm still in the early stages of planning. The tank's currently home to some big cichlids that will be rehomed soon, so I'm looking for ideas to get started.

The existing substrate is a coarse white gravel that I want to replace entirely. I've considered using black diamond blasting sand (BDBS) as the top layer, since it looks nice and is affordable in bulk from Tractor Supply. However, I know BDBS is inert and won't support plant growth. To address this, I'm thinking of using a nutrient-rich substrate as the bottom layer, with BDBS on top. What would be a good choice for this bottom layer?

As for the plants themselves, I'm still researching options. Some that I'm considering include Zosterzon swords, Vallisneria, Moneywort, Cryptocoryne, micro swords, and non-substrate plants like Java fern and Anubias.

I've been thinking, wouldn't over-dosing with fertilizers and nutrients have an impact on water hardness? Considering my tank has shrimp, which are super sensitive to water hardness, it's a recipe for disaster - both for my tank and my own sanity.

[Freshhub]

As for invertebrates, I'm thinking maybe some apple or mystery snails could work in the future, but that's about it. I've had some snails before, but with the fish I've had since then, like clown loaches, it's been a no-go - they just wouldn't coexist. I don't have any experience with shrimp, but I'm not ruling out the possibility of having them in the future either.