How do clams release waste (nitrogen spike question)

[warrenmichaels]

Does nitrogen spiking play a role in how many clams can be kept in a tank? Do clams hold waste until it accumulates and then let it out all at once (like fish), or does it seep out gradually over time?

(If it seeps out gradually, then it would seem like spiking is far less an issue, and more can be kept per unit of volume.)

Thanks