We offer three different types of fuel filter media (cellulose, microglass, stainless), and they all have different uses for specific applications, fuel types, and certain manufacturer's filtration requirements for their injectors.
Some manufacturers recommend a very fairly fine filtration. However, in the context of the total fuel system, we want to filter as coarse as possible. Finer filtration will increase maintenance, and if ignored, may lead to an immediate risk to your fuel pumps (overloaded) and/or engine (if it is starved for fuel in certain circumstances).
On the other hand, our customers have reported us that running our stainless steel elements on Bosch based injectors has shown single digit percentage degradation of injector performance over a year. (in many cases, they report zero degradation. There are many variables with fuel maintenance, so be advised this information is anecdotal, whereas Injector Dynamics' product requirements are from scientific findings. Nonetheless, this is typically not going to cause immediate risk to the engine and relaxes risk of overloading the fuel pump(s).
Generally, we cannot provide accurate filter service interval since it depends on element type, fuel maintenance, source, and environment...not miles driven or time. However, stainless elements are somewhat forgiving because of the more coarse filtration and the inconsistencies in the mesh will allow some larger particles to pass. We can typically recommend annual cleaning of stainless elements under most circumstances.
You can clean the stainless steel filter element by backwashing it with fuel; however, ultrasonic is the best option. You can purchase an ultrasonic cleaner online for cheap, or you can take it to your local hydraulic supply and they can do it for you. Do not use acetone or any cleaner with acetone. (i.e. some brake parts cleaners have acetone) Lastly, handle the element gently and do not scrub the mesh with a brush, as it is delicate and could be damaged.
However, microglass elements will require more frequent service and cannot be cleaned. It is finer filtration and requires more frequent attention and service. We recommend checking the fuel pressure before and after the filter to determine when a change is required. (change at ~5psi loss) You can simply put a mechanical gauge before the filter, or you can use a pressure sensor and port it to your PCM for datalogging alongside the other sensor you have after the filter. (check with your tuner on how to do this)
It is also worth mentioning cellulose elements that are used in gasoline only applications. These also cannot be cleaned; however, due to the far lower maintenance requirements of gasoline fuel versus high ethanol blends, cellulose filtration can be serviced annually with little worry.