Sorry for the loss, it always is a downer when animals die.
I'm curious as to why you are running a skimmer in the first place? Seeing as how you are dosing what the skimmer is pulling out. Is there another reason for running the skimmer? IMO I'd pull the skimmer and put a HOB like the Seachem Tidal. I like this as it has a built-in surface skimmer and self primes. Can't go wrong with an Aquaclear either. A HOB will also help with oxygen exchange.
I'm curious as to why you are running a skimmer in the first place? Seeing as how you are dosing what the skimmer is pulling out. Is there another reason for running the skimmer? IMO I'd pull the skimmer and put a HOB like the Seachem Tidal. I like this as it has a built-in surface skimmer and self primes. Can't go wrong with an Aquaclear either. A HOB will also help with oxygen exchange.