Near the tank no. Just make sure you are not getting dead leaves in the tank or spraying them with pesticides which could get into the tank. I have a ton of plants in my fish room growing out of my freshwater tanks, pothos, monstera, palm, and many more. On a side note those plants use co2 I dont know how many plants she is planning and what kind of ratio of plant vs the co2 levels but I feel they help some. I purchased a good not top of the line co2 monitor it reads 416 outside which is about where it should be, living area is around 1100, fish room around 600 and basement is around 800. I get the living area has 2 adults 2 cats and a very large dog while the fish room only has me for a few hours a day for the most part. I have a group of 8 people that come over for a game night once a month and we are in the fish room so 9 adults in a 600sq' room for about 6 hrs and co2 levels have only gotten to around 900 at most.
