Normal Nitrate Rise?

[GoGators]

Whats the normal ppm jump per day on nitrates? The reason I ask is because it jumped 10 ppm in 24 hours. My fishless cycle ended about 2 weeks ago, I now have 5 zebra danios, 2 dwarf guarmi, and a small bristlenose pleco. I'm pretty sure I overfed. I gave them 3 total of tetra crisps last night, then this morning I put in about 5 hikari micro wafers. I'd like to keep my nitrates under 20 with weekly 25% changes. Is that possible? Nitrates are 5-10 in the water going in. It's a 29 gallon tank with a penguin bio wheel 150, lightly planted.

 

[alchemist]

I would keep a diary for a couple of weeks and see if you spot any pattern - You may naturally be seeing this increase - also bear in mind that the nitrate test is not very accurate (IMO) - you have to be religious about following the test instructions.
Other causes could be the excess food breaking down, or perhaps excess waste getting kicked up from your substrate when cleaning.
There are so many variables I don't think it is possible to quote a daily figure.