Did I read this right, you were feeding 31 to 40 shrimp per day?
If so you are killing it with kindness.
That amount of shrimp, becomes a lot of waste, in the form of ammonia, as you have already found out.
And to process that much ammonia, you need much heavier filtration than you have, daily water changes, and a giant protein skimmer might be required for that waste load, if you continue with that heavy feeding schedule and amount.
And as general practice, it doesn't need, all that food.
Of course it will always beg for more, but it doesn't need that much, or is it even good o feed that much.
In nature fish live in a feast or famine world, so they eat as much as they can, when it is there.
In nature most fish don't get to eat once per day, sometimes they only eat once every 3 days or more.
So the expectation that they will be fed daily in an aquarium is not processed, they don't have a the human regulator concept, "I'm full, I can stop now".