Seachem ph alert?

[Vikkiog]

Hey guys, thought I'd give it a go as it was on sale, however.... The middle part that changes colour to indicate ph has come off and must be somewhere in the tank and I was wondering if any of you knew if it might be harmful to the fish if I can't find it?
There is a little bit of the colour changing part left on it so I can still use it anyway
Thankyou