I have a 100g with 120w of lighting, no co2, i only have a few low light plants,couple of vals, and 3 or 4 other low light plants. Do i need some fert/root tab things, if so where do i place them, what is the best brand? Which liquids do i need, if any? Also i have apple snails and trumpet snails. Will they eat the tablet things? Will they be ok together? Info very much appreciated.