Sorry, I should have made myself more clear. :blush:
There are many hardy plants that grow under various conditions. Also in nature some plants grow in acidic conditions, as shown by this link. So its definitely possible to grow plants in water whit a low pH. However for most (sub)tropical aquariumplants the ideal pH is somewhere between 6 and 7. below pH 6 plants usually grow significantly worse. Lack of light, tannic acids and tannins make blackwater also less suitable for plants.
for example this is Microsorum trident in the planted community tank (pH 6.5);
the same plants are growing in the 10liter tank, but those are coming from a tank with pH 5.0.
since C. cordata is quite a hard to find plant here I prefer to keep it under the best conditions I can offer. As a result it started to bloom B) :
Stefanie, the Pangio semicincta is like Houdini. I kept them in this tank until I changed the substrate. Their caudal fins where occasionally nipped by the red tail puffers so they should be moved anyway. somehow this little fellow stayed hidden in a completely emptied tank, and every time I tried to catch him, he disappeared. Until I cleaned out the filter last week and I found him, apparently he could not only get in there but also out again… :huh: