Thank you all for answering. I can't do anything but sand, I'm stocking with Neolamprologus Caudopunctatus, Tanganyika Cichlids, they dig pits (sometimes) to spawn. That is the one draw back of soil substrates, (I have 7 other tanks with mineralized soil capped w/3M) can't keep diggers.
Emilie, I also want to know more about your discus tank, it is beautiful. Lighting, co2, temp, how many and how often on the root tabs? But the most important question "will you come to my house and make my tank dat purdy?"...<vbg>
It's a simple, low-tech set-up. No C02, just regular dosing with excel - max. 2 X week, along with Flourish Comprehensive Supplement - also 2 X week. Root tabs in my 75 gal: - 8 tabs, replaced every 4 to 6 months. Lighting: 2 X 39W T5HO - 8 hrs./day. 84 F temp for the discus - pH constant @ 6.6-6.8 - Kh & Gh in normally accepted ranges - I don't check this very often.
Plants are easy-care, doing well: 3 Sword varieties, Hygros, Ludwigia, Anubias, Jungle Vals, C/S Vals, Red & Tiger Lotus - nothing fancy. Occasional changes of plants - Pruned/trimmed every 2nd week.
Water changes - 2 X week: 50%-60%. Good filtration: 2 - AC 110's with filter floss & Purigen on regular basis. Cleaned/rinsed frequently - crystal water clarity on a consistent basis.
Substrate is white silica PFS - light - 1/2" in front, max. 2" or so at rear.
If you lived fairly close by, I'd be happy to help you get yours up the way you want it - it's all a matter of personal preference - glad you like mine, I do too.