Tank data not changing

I have had my 20 gallon tank for two weeks now. I am currently cycling it with 5 zebra danios. For two weeks my stats have not changed. My ammonia is either.25 or .50. I do a 25% water change when its at .50 and a 10% water change when its at .25. The ph is always 6.8 and the nitrite and nitrate are always at zero. Is their something wrong because the ammonia is not changing. I use two filters, one penguin biowheel filter and one top fin power filter. My fish seem fine and i have had no casualties yet. I feed them 1-2 a day but for the last 3 days i have not fed them. And yes, i do use a dechlorinator that gets rid of chlorine and chloramines (my water company doesnt use chloramines though)
I have not been using any medications.

Photos are down the page

Here is my ammonia tests in order from day 1-15
"0
0
0
.25
.25
.25
.25
.25
0
.25
.25
.50
.50
.25
1.0!!!
.25 Phew
.50
.50
1.0 OMG IM SO ANGRY

"All nitrite is at zero, all nitrate is at zero" (since no one has read this i will have to put it in table form!)

Nitrite:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

Nitrate:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0



I was using dip and read test strips from mardel. These past few days i have been using API freshwater master test kit that uses liquid tests.