May have to go inert on the raised areas. Can't think of anything that won't do either of those, except thoroughly rinsed inert substrates like blasting sand, pool sand, eco comp. etc... and poured through a tube to the bottom (gravel siphon tube if its long enough) and still may be a little cloudy for a short time, but nothing fatal for your fish
Could always stick root tabs in the raised areas to compensate for the lack of nutrients if you like. Or start without and add those later if you feel its needed
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