Dirt and Very Soft Water?
I did a search, but I didn't really get the answers I'm looking for. I also read the substrate guide.
My tap is about 8dgh and 8dkh.
I have a 55 dirted with miracle grow and clay and capped with pea gravel. It is moderately planted. It's been up for several months and is running at about 8dgh and 8dkh. No ferts, no CO2, nothing but the substrate, light and water changes.
I'm getting into soft water apistos. I've got RODI and I'm decent at keeping my first tank at around 1dgh and 2 dkh. I use pea gravel in it.
I'd like to get the tanks planted for the apistos, while maintaining the soft water. Obviously, an increase in dkh wouldn't bother me, but I need the dgh at or below 1. Would a miracle grow capped with gravel stay inert in terms of water hardness?
TLDR; I need my plants to survive in 1dgh with no ferts and no co2, what substrate can I use that will allow this and not change the GH?