What the previous poster said is generally true. It’s difficult to have big fish and lush plants to co exist. Most nature aquariums have only small schooling fish that you can barely notice they exist.
It’s difficult, but not impossible. I’ve seen many heavily planted discus and angel fish which are big fish but don’t dig. I’ve been experimenting in the last 6 months to keep plants with medium to large CA and African in a 75 gal. My fish are more challenging because they are not just big but also dig. I’m riding through a learning curve to gradually get things in order, and hopefully will work out.
First I selected only easy low light epiphytes that don’t need to root in substrate, which included java fern, anubias, Buce and bolbidus which I superglued to rock, My fish included a 10” Vieja Bifas and a 10” GT plus half a dozen 4 to 6 inch African and CA. None of the eat my plants, but they can be rough on plants when they attempted to rearrange the plant scape. I had to pick up loosen plants just about every day to re glue them since it’s take time for them to develop anchoring roots.
Initially I did not dose fertilizer in the assumption that heavy fish load will produce adequate nutrients. I was wrong because while fish waste is rich in nitrogen and phosphorous, my plants were showing severe potassium and iron deficiencies. So I started dosing potassium sulfate and micro nutrients containing iron. From what I read, fish waste is rich in iron, but it is not the soluble form plants can absorb.
Another big problem I had was algae invasion within weeks due to high organic waste load, The most devastating algae is black beard algae covering the foliage and hardscape. So I started dosing Flourish Excel which is a carbon source and an algaecide if dosed at 2x recommended dosage. I also sprayed peroxide to exposed bba during WC. That took care of the algae.
Before dosing excel and nutrients, my plants were dying from nutrient starvation and suffocation by bba. I lost 2/3 the plants I started out before they started showing some life and green growth. But the growth rate was too slow to my satisfaction, so I made a leap to install CO2 injection. CO2 is like steroid, and the plants started to take off and the algae went away. The faster growth also accelerated plant rooting on the rock so I need not re glue them as often. The plants are looking better now. I still have a few algae here and there, still dosing excel to combat bba on hardscape, and still tweeting the balance for perfection