He guys... so my 180 gallon has been running for about a year now and every thing has been going pretty well with it for the most part. The current inhabitants are my marble motoro ray, a peacock bass, and an earth eater. The filtration i have on it right now is just a big wet dry filter and a uv sterilizer. My problem is that lately i have been experiencing small amount of ammonia in the aquarium of about .25ppm despite the light tank stock. Is this because of innadequate filtration? I was thinking about getting a canister filter such as a fluval fx5 or something, but would this help?