Should i still feed my Amano and Crystal Shrimp when they have a lot of Algae in their 20L tank?

[Thne]

I've been alternating feeding 4 Crystal and 2 Amano Shrimp every 2 to 3 days, giving them a few shrimp pellets, but their tank recently has grown a lot of Algae between cleanings. I cleaned the Algae today (the tank was very green after only 6 days of not cleaning), leaving some on the rocks in the tank for the shrimp to eat. 

I'm considering feeding them less, as I think they might not be eating the algae on the hard surfaces, or the moss in the tank, and that I may be overfeeding.

 

I've attached a few pictures of algae on the rocks and moss, and was wondering if this looks enough to leave the shrimp more days between feedings than i have been doing? Thanks for any advice, it's a small 20L tank that's been settled with shrimp in for around 8 months. 

 

I recently had a berried Red Crystal have babies, and then subsequently have them all die in the tank, and after research i think it might have been from overfeeding or heat fluctuations that the babies couldn't survive, but the adults were used to.