Whats the best substrate for my fish?

agree with aquella about the sand. CARIBSEA BRAND is all i use. tahitan moon sand looks great. i also like the eco completes. avoid using the cichlid subrate cuz it will buffer ur ph and ur tetras will not like it. i wouldnt recomend shrimp either. between ur shark and chinese algae eaters. ur shrimp would be nice kabobs. depending on ur filtration and how often u do water changes. u could squeeze a couple more fish. i would definitley get rid of the chinese algae eaters though. before u encounter aggressive issues. do me a favor tell that pet store employee needs to read up on his fish if he/she values their job. i do not let any fish be sold until my customers know what it is. how big it gets. what it eats and its temperment ect.