Hi mackay.
It looks like your a-bacs have grown at a good rate and have started to produce some nitrite hence the 5ppm. I feel however though that it is far too soon to be seeing any nitrates as a result of n-bacteria growth and this could be background nitrate in your tap water. In my area (doncaster,uk) my tap water background is 31ppm!!
This is probably responsible for the nitrate showing. It does look good however for nitrite production. Only re-dose your tank with ammonia once your ammonia is barely detectable at around 0-0.25ppm then once it is processing in less than 24 hours you can re-dose every 24 hours only. this will stimulate n-bac growth and the ultimate aim is to get both amm and nitrite readings undetectable 12 hours after adding ammonia. I apologise if you already know this but i assume you are perhaps new to cycling. if not then Im sorry mate.
all my 3 tanks took around 3-4 weeks to cycle fully before I could add fish but all are doing fantastically now. patience is the key to cycling and also keeping a log of readings and times of addition of ammonia etc.
good luck mate
paul
