[tang daddy]

20 ppm nitrates is not bad if you're keeping fish only, if you're keeping soft corals and most lps that will be fine aswell. An exceptable level of nitrates for Lps and softies is 10-20ppm. Sps 0-2ppm, you should also consider a clean up crew like a few snails and hermits once you see hair algae grow.

Be carefull when Introducing inverts, be sure to slowly acclimate as they are far more sensitive than fish, and the reason why I said abit of liverock was to add some diversity of bacteria, pods and bristle worms and sponges and featherdusters, those will help eat unfinished food aswell as filter the water. Just make sure the liverock doesn't have any aptaisia and your good to go!