use pump dosing system to test retention time for strings

[monroews]

Using capillary action to set the flow rate for the strings wont' work in practice.

• capillary pores will clog with biofilm and thus we can't use this as the method to set the flow rate
• flow rate will be too low
• You need to be able to measure retention time as a function of flow rate

Thus I recommend using the dosing system that you created for the chains when testing the new strings.