Discus fish aquariums if planted require installing soil under the gravels in order to feed the plants and grow them for the long term.
I strongly advise you to use soil under the gravels of your Discus aquarium despite the type or color of your gravels or sand, then install your plants.
The Aquarium Soil Substrate 1 Liter has the below specs:
- Composed of organic and inert ingredients providing all essential elements.
- Long-lasting fertilized plant substrate lasting up to 12-18 months.
- Prolongs water exchange periods.
- One bag Covers approximately 12″ x 6″ at 1″ deep or 6″ x 6″ at 2″ deep.
- Black in Color.
