Cilantro?

[TigTag97]

Okay let me start by saying this is my first system and i made it in like 20 minutes and i know im probably doing most of it wrong but i was looking for some help. Ive got a little half gallon tank with a betta and a snail. Theyre both happy together amd ive treated the water Api Quick Start to add the natural bacteria to convert all that fish waste into nitrates, but the plant of choice is cilantro ( for no specific reason i just read that its a plant able to be grown this way) and its slowly dying, very slowly. Although it looks like some of it is growing, nevertheless i want to know what im doing wrong and how i can grow more. Also, i made a cup to fit around the roots to block any light but im not sure if its helping much. Advice?

[Oliver]

In order for us to help you, we need to know your water chemistry measurement numbers.

Oliver