If your test is the API one I think grey, along with green and going back to blue after being purple all means that the nitirite is off the scale the test measures.
FIshy55.

It just means lots!!
How do you manage to change the 2nd line of your title all the time, I have been looking for ages how to do this but can't see it.
Fishy55.
Ta for that, have now changed my 2nd line and corrected the spelling mistake in the first line.
Fishy55.
Yeah when it turns grey it means its gone off the scale.
Might start turning a transparent black colour (if that makes sense).
and would appreciate any advice on how much Ammonia I should start adding once it is in my filter? I am currently adding 1.8ml of Ammonia / 3 ppm. I am sure PDsimon has alredy advised me on this, but to be honest I cannot find where lol.

Cool thanks Si for your advice here,![]()
I don't think you'd need to do a waterchange just yet - I was reading through the other thread.
My nitrites could have easily been 100ppm so I decided to do a water change because I felt it would improve the conditions for the bacteria to replicate. It may have done because it now seems to be cycling atleast the ammonia that I put into the tank. I HOPE!
You're only on day 11, I'm on day 41 now and I still havn't come out my nitrite spike (my ammonia took much longer to go down too). So what I'm saying is don't feel the need to try and optimise growth so quickly because moving the filter around will possibly stall the cycle too.
Hope this helps. Things are going well and hopefully the mature media will boost it even more so.
oh and if you want to know what nitrites look like when they're 0, test your tapwater (assuming that comes out at 0)
I wouldn't change it because of the media, all the mature media is doing is bringing in bacteria, they need the same conditions as the bacteria you've already got going.
Hopefully the media going in your filter?