Starting up with a lean substrate

A South American tank, with lots of wood and leaves on the bottom. The planting is simple: Echinodorus bleheri and Echinodorus parviflorus, two sword plants that naturally belong to this region.

This tank is also an experiment. I wanted to see how far you can get with a fairly lean substrate: a 2 cm layer of MA-Gen 1.2 (akadama with a very low fraction of organic matter, just over 0.5 %) and volcanic rock. For lighting I started with an inexpensive LED lamp.

That soon turned out to be too much light. The Echinodorus struggled with it, and before long the leaves showed a shortage of nitrogen and potassium.

After a month and a half the fish were added: Apistogramma viejita, Nannostomus marginatus and a brown bristlenose (Ancistrus sp.).

The photos are from later, in January and April 2026. The large photo shows the damaged leaves of the Echinodorus.