If you're reading nitrates at all then yes, I'd say the cycle is complete, seeing how nitrates are the end part of the cycle. But if you're not reading anything at all, I'd keep an eye on it. Maybe you have enough algae that it's eating all the nitrates, or your cycle isn't done. If you see any ammonia or nitrites I'd be concerned for the well being of the fish. If it were a fishless cycle I'd advise you to not do a water change and let the cycle finish it's course. Since it's a fish in cycle, if you read ammonia or nitrites, I'd suggest a partial water change to lower ammonia or nitrites, thus lowering the toxicity of the tank, giving your fish a fighting chance.