How to quickly test 10 different startup ideas in limited channels

Hey guys, I'm curious what methods you used to gather quality feedback from your potential customers in the early stage to test your startup ideas.

I've created a simple landing page which includes a prototype and video of my SaaS product along with a step by step process of how to use the service. I'm recently distributing it to various channels including slack and facebook communities interested in productivity apps, but I'm afraid I wouldn't be able to use the same channels for 9 more ideas that I'm trying to quickly test within 2 month.

My only goal is to gather feedbacks and find out which of the ten ideas solve the actual problem that people are facing. I want to validate which is worth developing further.

It would be great if you could give me any advice especially in Marketing/Growth Hacking point of view. Thanks!