Best way to monetize a website in the planted aquariums niche?

Hi all,

I have a website/blog in the planted aquarium niche, it's been online since 2014 when I posted some very good articles which ranked well. Then I posted like once every few months and so on.

Now it sits pretty good on Google's first page for a good number of important keywords.

It has Adsense on it from the beginning but it's earning so low, like $1-$2 per day (in the best days), in total I get around $30-35 per month from adsense earnings.

Since 3 months ago I started to work again on it, posting on social media often (Facebook, Insta, Pinterest) and I managed to get it up to 500 users per day (850 pageviews), with a total of around 11k users in the last 30 days.

I've also started to build an email list since February of last year.

I could try to up those numbers and get it to 10x of what Im getting now, but that would really multiply my adsense earnings? And if so, I'd be at around $300 a month, which would be awesome but I want to earn more from it.

Would appreciate some fresh ideas from you guys.

Thanks!