First off check your dechlorinated tap water, nitrate levels of 5.0 are not unusual straight from the tap. It is not harmful at that level.
As to CYCLE, I never use it, I like the old fashioned way of seeding the filter and slowly increasing the tank population, letting the tank go through a series of mini cycles.
tested again. the water is still the same... nitrate is 5 but amonia and nitrite is ZERO. fish are all fine, swimming and eating good. i'll keep on checking on the fish and water values.... last question... i currently have an xp3 and an 18" bubble curtain. do i need to put a bio-wheel filter (marineland)? to have a better place for beneficial bacterial growth? for all that responded to my question