Api Nitrite Test

[DJayP]

Ok, so im on day 16 of fishless cycling my 90ltr tank. I add ammonia every day as within less than 24 hours it drops from around 3/4ppm to 0. Now when i do the nitrite test, add the 5 drops the water instantly turns a dark puple colour, then i shake it, still purple but then after i have left it for 5 mins it turns to a light blue colour(not a colour on the test card either) So is this normal? I used the kit on another tank about 5 months ago and i dont ever remember this happening. My nitrates are currently at 10ppm.
Thanks
Neil

 

[Amunet]

Sounds like your tank might be done cycling?
Doesn't light blue color mean nitrite is at 0? That's what color it shows on my card to indicate a reading of 0 nitrites
Not sure why the water would turn purple at first though. That's kinda weird.
How old is the tester you're using?

 

[celaeno]

the result you should be looking at is the one after 5 minutes of the first shaking of the test tube. so if it's purple, you're not done cycling.

 

[DJayP]

The drops from the bottle turn purple staright away in the test tube, after shaking the test tube its still purple but after a few minutes the colour gradualy gets lighter. The test kit is about 6 months old at the most.

 

[dizzied]

It's very possible that you have so much nitrites that the test could not measure it properly. There's nothing wrong with that, especially if you're using a large amount of ammonia to cycle the tank. This often happens to me when I'm cycling.

Watch the nitrates, they'll let you know when you're done. Wait for the big spike and then test everything. The nitrite test should stay blue, as opposed to going from purple to blue.