way off topic!

So, I'm watching the tv show Mayday. British airways flight 38 suffered a fuel problem approaching Heathrow. Turns out ice crystals clogged the fuel heater (manifold system with smaller tubes at that point).
There's some moisture in all fuel, you can minimize it but not totally eliminate it. I'm fairly experienced in that but I usually operate in temps above -40c in the winter. I use fuel heaters and fuel additives in the winter to lower my gelling point.
Turns out the fuel temps were high enough for the ice crystals to get sticky during this event (-20c) and cause them to clog the fuel system at the heater.
While it might not be completely analogous, it makes sense to me as somewhere near 0f I find it beneficial to keep my windshield cold to help prevent snow from sticking to it.  Anyway, it appears there is a fine line between preventing gelling up and ice clogging the fuel line. If it's cold enough, the crystals will remain separate and pass through.
I'm not an aviation geek, only about 3 hours in the left seat before I decided it's not for me. If you've read this entire post and made sense of it, I'm sure professional help is available and you should seek it out.😁

Been looking at maps & needed a break, brother from another mother just retired from law enforcement and moved to a small rural town in western North Carolina so summer travel plans are being reconfigured

Ice crystals in jet fuel, makes one wonder what the gelling point is of avgas and why this is not a problem flying so high in freezing temperatures. All my years freezing on the flightline I never thought about this before.

Minot AFB at -40 in a snow storm uploading B52’s with special weapons and watching fuels pump em full of avgas while de overs struggled to keep em clean was a real bitch.

I know the SR71 used JP7 jet fuel and it was around -60 when being refueled from a KC 135 tanker and that the ST71 used the jet fuel as a coolant for its engines and systems

Was that the one where they loaded way too much fuel treatment causing the fuel to gel?

Been looking at maps & needed a break, brother from another mother just retired from law enforcement and moved to a small rural town in western North Carolina so summer travel plans are being reconfigured

Ice crystals in jet fuel, makes one wonder what the gelling point is of avgas and why this is not a problem flying so high in freezing temperatures. All my years freezing on the flightline I never thought about this before.

Minot AFB at -40 in a snow storm uploading B52’s with special weapons and watching fuels pump em full of avgas while de overs struggled to keep em clean was a real bitch.

I know the SR71 used JP7 jet fuel and it was around -60 when being refueled from a KC 135 tanker and that the ST71 used the jet fuel as a coolant for its engines and systems

Ice crystals are separate from gelling. Ice is the water in the fuel and diesel will gel which is thickening of the fuel itself, basically the paraffins  solidifying. #1 diesel or kerosene has a much lower gel point. As I understand it, jet fuel is basically #1 fuel, or maybe further refined than that.
 I'm not sure about avgas, but the name suggests it's gasoline rather than kerosene. If so, I'm unaware if gas can gel, I've never heard of that happening. The only cold weather treatment I've heard of for gas (heet, etc.) is stuff that deals with the water contamination.

Was that the one where they loaded way too much fuel treatment causing the fuel to gel?

Not from the tv show. It came to the conclusion that the fuel temps were just warm  enough to cause the ice to get sticky rather than flow through the system.
I didn't know too much additive could cause gelling. I haven't gelled up for probably 40 years now. I think the skirts over my tanks help keep the engine heat on the tanks as well as the return fuel being hot. I used to use power service additive but now use Howes (no reason for switching) when ambient temperature gets down below -10.

I saw a YouTube video talking about air accidents or close calls and there was something about a plane that they had accidentally miscalculated something they put in the fuel that was stopping injectors up. I'll try to find it again but I can't promise anything. Edit: found it, wasn't antigel it was antimicrobial additive. https://youtu.be/E4Qclymu2EA?si=ex5fx1NqTXQCjEey

I saw a YouTube video talking about air accidents or close calls and there was something about a plane that they had accidentally miscalculated something they put in the fuel that was stopping injectors up. I'll try to find it again but I can't promise anything. Edit: found it, wasn't antigel it was antimicrobial additive. https://youtu.be/E4Qclymu2EA?si=ex5fx1NqTXQCjEey

I've only had to deal with algae in my tanks about 7 or 8 times in 40 years. When you kill the algae it gets trapped in the filter and resembles coffee grounds. Once you've done that get ready for several filter changes in a short time frame!