ummmmm, Racor became a division of ParkerHannefin about 15 years ago. ParkerHannefin is probably (or close to) the worlds third largest manufacturer of advanced filtration products and is probably close to becoming one the worlds largest manufacturer of industrial filtration (additively through the acquisition many such 'divisions').
Algae is a species that depends on photosynthesis for its metabolism. So, unless your tank has an inbuilt large window that allows lots of sunlight into it .... you dont have much 'algae' in it. Since at least the 1940's the defined primary biologic species that contamintates fuel oils is a FUNGUS: eg.: cladosporium resinae ... a RESIN forming fungus (aka "kerosene fungus"). The particulates that 'grow' and propagate ***inside*** a (contaminated) fuel tank are the decomposition products of the fungus (cells), and the oxidized fragments of refining process (alkenes, etc.) that the funguses, et al use as a nutrient source. So, unless you are 'blanketing' your fuel with nitrogen gas, adding the correct enzymes, etc. to keep the particles in suspension and to keep these particles from 'agglomerating', actually *use* the bulk of your fuel instead of letting it degrade IN the tank.... you dont need to filter it other than an in-line Racor (train).
Some of the newly developed enzymes for 'tank cleaning' show advantage in keeping the particles from sticking to one another and also to 'release' them from the tank surface walls - also without the agglomeration (smaller particles becoming larger and larger particles) problem.
As far as Algae-X .... probably better to wear it on your wrist to prevent sunburn than to waste time & $$$$ with it on your fuel system.
BTW - Chuckbear is correct -- an onboard recirculation polishing system is an extremely cheap and easy to build and maintain system (you just need a high turnover/ high flow pump to do it) .... and prevents premature plugging of expensive "racor" type filters, so your ROI is gained in ~1-2 years or less if you are a 'moderate' user of fuel - most weekend sailboaters are not 'fuel users'. The recirculation polisher's chief benefit is the removal of the 'seed particles' so you attenuate the later 'agglomeration' --- and 'particle storms' that kill filters.
BTW - Although I didnt stay at a Holiday Inn Express, I am a physical chemist and Mechanical Engineer that has spent a working lifetime in the engineering and designing such 'filtration systems' ... Keep it simple; clean your tank or be sure that your tank is clean, only fill the tank with what you NEED and a small 'reserve', use vacuum/pressure gauges on your Racors so you know WHEN to change them .... couldnt be simpler.
