Unity .GetParticles() high CPU spike - unity3d

Question

Im using .GetParticles() on a particlesystem to then destroy the particles when they are outisde of a certain range. My script is below and the particle system variable is cached. I attached the deep profile picture of what is taking the CPU and it points to GetParticles(). I can't find any documentation to why this would be a bad approach, as the script is only attached to one single game object.
Any insight appreciated, thanks!
private void Update()
{if (Time.time > (delayTimer + 0.02f))
{
delayTimer = Time.time;
transform.position = new Vector3(transform.position.x, Water.transform.position.y - 2f, transform.position.z);
//Gets the change in the waters height and resets it
var waterHeightChange = Mathf.Abs(Water.transform.position.y - waterHeight);
waterHeight = Water.transform.position.y;
//Gets the distance to the top of the water to pop the bubble if surpassed
var DistanceToDestroy = Mathf.Abs((Water.transform.position.y + (Water.transform.localScale.y / 2f) - .15f) - transform.position.y);
//Creates a particle array sized a the emitters maximum particles
//Gets the particles from the emitter system and transfers into array of particles, returns total number of particles
//Only called on occasion (once at start really) to make allocation as minimal as possible
if (pSystemParticles == null || pSystemParticles.Length < pSystem.main.maxParticles)
{
pSystemParticles = new ParticleSystem.Particle[pSystem.main.maxParticles];
}
int numParticlesAlive = pSystem.GetParticles(pSystemParticles);
for (int i = 0; i < numParticlesAlive; i++)
{
//Changes the height accordingly for each particle
newPos.Set(pSystemParticles[i].position.x, pSystemParticles[i].position.y, pSystemParticles[i].position.z + waterHeightChange);
//Grab the 'y' positional height relative to the emitter
var particleHeight = newPos.z;
if (particleHeight >= DistanceToDestroy)
{
//Deletes particle if needed
pSystemParticles[i].remainingLifetime = 0;
}
}
//Sets the particle system from the modified array
pSystem.SetParticles(pSystemParticles, numParticlesAlive);
}
}

Answer 1

I'm not sure why you get this spike but this seems to be outside of your control. Maybe you could use the Collision Module, put an invisible plane above your waterline where the particles should stop and then set up the collision module such that the particles lose their whole lifetime when they collide (Lifetime Loss = 1). That way they should disappear when colliding with the plane. Could be faster because particles would never have to enter the C# world plus it's a lot less code to write.