 Substrate for high pH / low light system?
Just curious what people have been using for high pH / low(ish) light systems? I've been running heavily planted aquariums for years (going on a 2 decades now) with fairly low light levels, no CO2 additions, and no special substrate but the times they are a changin'! I moved 2 years ago to an area with very, very high pH and hardness (water comes out of the tap at 8.3 with the mineral content to match!). After fighting a losing battle to either force myself to buy RO water for all 7 tanks or otherwise modify the water, I've conceded defeat and am trying to find set-ups that work with the new conditions. Currently, my tanks are all running with half a dozen anubias types and a couple java fern morphs. All are thriving and spreading like mad. A couple of my Amazon swords oddly enough also survived the change and are sending out babies. I'm still experimenting with what fish work here (previously used to breed dwarf SA cichlids in my planted tanks) and have everything from a tank of ultra fancy orandas & ryukins (yes, I successfully do 5"+ goldfish in a planted tank!) to a tank of breeding kribs to tanks of assorted community livebears.
Soooo...I am about to set up a 37 gal tall tank. Lighting is going to be fairly low again (got the tank, lights, filter, heater etc for $10 still in the box..can't beat that!). I want to do a dark substrate but I'm wondering what other people have found for hard water conditions where I do NOT want the pH or hardness to drop. So no peat or other acidifying substances. Also, since I had promised that the last tank was going to be the last tank (ahem), I'm trying to go on the cheap. Two juvenile blood parrots (already aclimated to the water here) and assorted dither fish are going to be going in...a gift from a moving coworker.
Ideas? | 
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