If you have a problem with your stored fuel, the last thing you need is to be hooked up with someone who doesn’t have your best interests in mind. Same goes for if you don’t have a problem right now, but are in the position where the potential exists for something to develop (i.e. just about everyone else). You don’t want to put your trust in someone who’s more interested in making money for themselves than treating you like the valued partner they should be considering you to be.
The fuels market is more competitive than ever, filled with entities that will tell you whatever they think you want to hear to get your money. Since they’re only considering their own bottom line, they have no problem inflating their real ability to fix your problem at hand. They have no issue telling you what they think you want to hear, even when it's not the best thing for you.
Generally speaking, "solving fuel problems" should entail a combination of things - chemical treatment, mechanical filtration or processing, and quality testing for diagnostics and the confirmation of success. Each has its value and its limitations. None are the be-all-and-end-all by themselves. Getting sucked into believing claims that don’t mesh with reality is a sure way to make your headaches twice as large.
Fuel polishing methods like tank bottom sweeping and fuel filtration are effective at what they do - removing physical contaminants from the fuel. Beyond this, when claims about preventing future fuel problems are being made, fuel polishers are tempted to overstate what your expectations should be upon completion of the job. This is especially true when presented by bigger money opportunities, like hospitals with large amounts of mission-critical stored fuel.
Your hospital fuel became unstable and developed sludge over time. Polishing the fuel will clean it up, but does nothing to keep it from going right back into that problem state over time. How many fuel polishers have convinced their customers that they can keep fuel from going bad in this manner?
Be wary of claims relating to how long the fuel is going to stay in the optimal condition you left it in. Polishing doesn’t do anything to prevent the problem from returning, nor does it really address what caused those contaminants to develop in the first place.
Polishing cannot solve a fuel microbial contamination problem by itself, either. A fuel polisher may remove water, but that only slows microbial growth which will return as soon as the water comes back (which it also will). Polishing definitely doesn’t kill microbes.
Polishing cannot turn high or low sulfur fuel in to ultra-low sulfur fuel. It might remove sludge which has a high sulfur concentration, but it won’t appreciably lower sulfur content in fuel. Some polishers have made the claims on fuel storage tanks that have sulfur content in the hundreds or thousands of ppm, that they can “polish out” the sulfur and turn the fuel into low-sulfur or ULSD.
What polishing does
What polishing doesn’t do
And in the interest of fairness, chemical methods have their limitations, too. Fuel additives can’t do everything and there’s a limit to the cost-effective scope they may have.
Some examples - additives don’t last forever. Biocides optimally last for 30-45 days (even that is situation dependent). So someone making claims about treating a tank once and having it last for months (or years) on end, they’re exaggerating claims as well. If a large fuel tank has 200 gallons of water in it, chemical water absorbers may have problems getting all of that, whereas mechanical suctioning of the water would be most effective.
Having a partner to keep your stored fuel healthy is always a good PM practice. It’s just as important to have the right one. A partner that doesn’t need to prove its legitimacy by unduly stretching the truth is the one you want to put your trust in.