Sorry for the noise issues you are having with your dosing pump. The X1-PRO is not silent and does have an operating noise that is audible. You can try to lube the wheels which will help dampen the noise of the collapsing of the tubing which you are likely hearing. Although the X1 PROT can be used for a calcium reactor it is not ideal for all setups. Those that have higher flow requirements will experience higher levels of noise as the pump is designed for continuous functions for low dosing applications. If you are looking for a quieter continuous pump great for calcium reactors I would suggest the Kamoer FX-STP. It has a large wheel with 6 rollers instead of a small wheel with 3 rollers which makes a difference in the sound produced by the wheels and tubing.