I have some dating sites (black dating, christian dating, general dating, etc.), but online one dating site has good traffic.

I mean, only one dating site has good traffic and the rest is not generating good traffic.

So, my question is:

Does Google de-index for creating same niche dating sites?
Do I have to change IP for each site?


i am not sure about your question...but i never heard google de-index pages for having many sites in same niche....or IPs....
unless you have some duplicate content issue among your sites i don't think same IP or same Niche is a problem.....

Having several sites in the same niche can not get a site de-indexed by Google. This may be possible, if you are using those sites to manupilate the system to get better ranking. Or, if you are using black hat search engine optimization techniques. As someone mentioned, I've never heard site that gets de-indexed by Google because its owner has several sites in the same niche.