I have a 30 gall.freshwater tank.
In this tank I keep 4 angel fish. 1 tire track eel (at this time approx 3 inch. Long) 2 small frogs and 4 chinese cleaner fish.
I faithfully do water changes every week ( 25 - 30% )
Up to this point I have not been testing the water.The tank has been a long established one.. but only in the last mo.I have added all the newcomers.. I transferred the old ones to a new tank
As the heading says... High nitrites and nitrates... but no ammonia// Now 2 weeks ago I rinsed my filter but did not change it... Could this be the problem and also.. I have increased the menue a bit as well to make sure all the little guys are getting something to eat as the angel fish are such Hoovers

Too many fish and too much water being changed. Cut back to 10% weekly.
The chinese algae eaters will get to be 6" and aggressive as will the angels. You should not keep them together. Add some plants to help clear the nitrates(wisteria,Anacharis).

Did you rinse the filter with sink water? If so, it would set back your bacteria. Add more bacteria to help in lowering the nitrites.
What is the PH levels? And how high is the nitrite?