is a sump enough filtration?

hello all i am wondering if a sump is enough filtration. i have a 100 gallon tank with one california stingray and one niger triggerfish in it. my sump is a 50 gallon rubermaid tub. the water flows into a home depot bucket witch has a top layer of foam to catch debris beore it gets to the bio balls. on this sump there is a also a 55 gallon take with one white eyed moray eel. both tanks running off one sump. my water quality is good but now there is alot of uneaten food at the bottom of the ray tank that doesnt get to the overflow. should i add a canister filter to it to help it out. this is obviously a fish only tsnk. there is about 10 lbs of liverock in the eel tank and about 10 lbs in the sump. im running about 500 gph through the 100 gallon and about 200 on the 55g any tips? all help is good help thanks