[RED 82~104 days] I attached aquatic plants to volcanic stones and they are very pretty. 

I'm using iron liquid fertilizer, but I'm thinking about increasing the amount

@@porcupineASMR41 red plants required specific wavelengths of light too, ive seen keepers using adjustable rgb lights, their red plants are thriving they are really picky at everything so maybe it's the plants' own problems, just switch to other pretty species if you find the reds' a hassel tho

@@rhzgrr Thank you so much for the detailed explanation. I installed 2 lights exclusively for water plants. As you explained, it could be a characteristic of the plant itself, so I'll consider a number of possibilities