Best diesel additive

All,
Looking for the best diesel additive, to prevent algae and growth in the tank. Over the past year, my use of the boat has been limited to short trips only once or twice a week, with downtime for additions and work done.


Biobor jf has been highly recommended, and has excellent reviews. Is that the one? I've heard the one must "shock" the fuel for first time users, can someone explain that? Thx!

Think of Biobor as an antibiotic, a poison actually, to be used to treat
biological growth in a tank.

I prefer to use an additive like Soltron to prevent growth and condition
the fuel.
Rather than a poison it chemically treats fuel to reduce the accumulation
of water among other things.

The best treatment of all is to prevent water getting in fuel in the first place.

In 1994, I was shopping for my first trawler. One that I looked at had been sitting for at least a year, so the seller suggested pouring in some Biobor as a "just in case" measure, before running the boat to a pre-purchase haulout. I did the research at the time, and followed up with a can of Biobor in the tank. I had no issues, at least none that were fuel related. I didn't buy that boat.
The boat that I bought had also been sitting for a while, but had been out on a couple of test runs prior to my own, with no fuel related issues, so when the time came for my own pre-purchase haulout, I did not use anything in the fuel and had no issues.
27 years later, never having used anything in the fuel, having left the boat for as long as seven months unused while enjoying a Snowbird lifestyle in the 9 years between retirement and Covid, I had a tank issue that led me to cutting in an inspection panel and emptying the tank. I found an "asphaltene" sludge, 1/8" thick, on the floor of the tank and nothing else. Zero evidence that there had ever been water in the tank, no trace of algae.
In the years between purchase and inspection, the standards for fuel cleanliness have improved dramatically. The days of water and other filter clogging stuff in the fuel are gone, along with the Sulphur content, due to the regulated improvements, first to LSD, then to ULSD.

There are recent threads that discuss this.

Unless you know that your fuel has contained water, you have nothing to correct with Biobor or any other treatment. Your Racor bowls will show the presence of water. Some have an alarm connected to a pair of pins in the bowl, that will alarm when water is detected.

Steve d'Antonio has a couple of good articles. Previous post is correct that biobor is good for killing bugs. But most important is to prevent water in the tank and thus preventing a lifesource for bugs.

I use Stanadyne fuel stabilizer as it's been recommended to me several times by knowledgeable sources.

https://stevedmarineconsulting.com/diesel-fuel-additives-part-ii/

Peter

Much like anchors, you will never get consensus on diesel additives. Everyone has their favorites for various reasons and some believe in no additives at all. Personally, I only buy Valvtect diesel which contains an additive package the includes BioGuard (their version of of a biocide). They also suggest adding extra BioGuard in the fall before a winter layup. Lots of articles and reviews online about the subject, but they will end up confusing more than giving the one "best' answer you are looking for. I'm in the camp that believes that additives may not help, but probably don't hurt, so I buy Vavtect exclusively if possible and also add some extra BioGuard or a stabilize for winter storage. I see no signs of any issues and hope to keep it that way. Valvtect diesel is no more expensive here than any other diesel at the docks.