Hi guys the attachment picture is my 3feet planted aquarium it established by 16th of November and at begining the tank was fully planted and by last week half of the plants were rotten and I removed the same soon after the establishment of the tank it turned like Brown and I don't know why here are the parameters ammonia nitrite and nitrate are zero and Gh is 4 dh and the canster is jbl e 930 and it contains seachem matrix for the bacterial development and for beneficial bacteria I used seachem stability and finally while coming to soil its Ada but the soil was purchased by 2018 and by 2019 I stopped this hobby due to some personal reasons and the soil was left at the same tank itself and by last November I restarted the same without washing the substrate just simply brought them out and washed the tank and added Ada super four and flourish tabs and installed the same soil and I don't use any drift wood and at begining I don't have any fertilizer except sunken all in one but even during that time I have left with my all seachem flourish nitrogen potassium phosphorus and iron but they were all expired so I brought sunken from local market but now I have all the fertilizers from seachem which I am using at my other tanks and now I am planning to remove other left over plants in tank and start from begining now tell me why this Brown color in my tank water is not getting eradicated kindly help me