It depends what you mean by too may
From a biological point of view Basically they will self manage their population in the form of limited size, so as long as they have bred up to that number the answer is no.
I have kept several thousand at a time in standard four footers and from an atheistic point of view I'd argue yes, this gets a big over the top ( but this is personal preference )
If you feel it's looking a little crowded ,take that as an opportunity to help some others out and prevent the ocean being raped of them by offering them up in the classifieds or passing some on to a friend.