Yea i have about 15 to 20kg of natural rough slate, aquired from the building site my dad was working on. This has never been a problem b4.
Heres my setup
280ltr fresh water with live plants, 1 Echinodorus(red special) 2 Echinodorus bleheri 1 echinoduorus osiris 2 cryptocoryne x willisii 2ludwigia glandulosa. Not using any ferts for these.
the slate. play sand sub, fish in sig minus 2 fm's.
roughly 50 to 60 ltr water change every week, water treated with 'nutrafin aqua plus' 15ml dose.
running a ehiem 2215 filter for near 3 yrs, cleaned every 6 months
Lights are 2 t8's on for 6 hrs a day
Think thats bout it, anything else i missed?