ive had my tank for about 6 months, 20 gallon, and ive only had plastic plants, but i think i want to try some real plants like one or two sword plants and a couple java ferns. would they be ok with sand or the coloured gravel? and i have an air pump would i need to get something to add CO2 as well? would this even work? i have 5 3" cichlids and a 4" bristlenose pleco, would they eat them and possible kill them? thanks in advance, you guys always answer my questions!