How to fix index bloat caused by subdomains

Hey guys,
I'm trying to improve the rankability of our website by fixing index bloat issues. Ourwebsites serves www.
Our site https://www.officernd.com hosts a SaaS tool and I discovered that there are thousands of non-www pages indexed that are mostly clients' log-in pages.
These are subdomains that our clients use in order for their users to go and log in to our SaaS tool from their websites.
For example - https://colliercapitalclub.officernd.com/login or https://thinktankev.officernd.com/ are such subdomains. To allow their users to utilize our tool, they have a "Member Login" page on their website that redirects them to a subdomain of our website which is a Login portal. So there are thousands of such pages indexed that IMO don't need to be in Google index.
What's the best way to fix this given the fact that each client's website passes link juice to our domain thanks to the current configuration?
Thank you!

 

There are a few different approaches you can take to fix this issue of index bloat on your website:

1. Use the "no index" meta tag on the client login pages: This will instruct search engines not to index these pages, and they will eventually be removed from the index.
   
   
2. Use the robots.txt file to block search engine crawlers from accessing these pages: This will also prevent search engines from indexing these pages.
   
   
3. Use the rel="canonical" link element on the client login pages: This will tell search engines that the preferred version of the page is the primary login page on your main domain.
   
   
4. Implement a login wall on the subdomains. This will prevent search engine crawlers from accessing the login pages in the first place.
   
   
5. Use the Search Console's Remove URL tool to remove specific login pages from the Google index.
   

Each of the above options has its own set of pros and cons, and it depends on your specific use case. However, using a rel="canonical" link element or a combination of a robots.txt file and a rel="canonical" link element will be the best option as it will keep passing link juice to your domain.

It's important to note that using the above methods may take some time to take effect, and you may have to wait for search engines to recrawl the pages before they are removed from the index.