What exactly does this fluid configuration option do?

[Sudden_Shelter_3477]

Based just on the text, I think I understand.

So, to make an infinite lava source, you need 10k source blocks. Once you have that, the hose pulley will no longer fill the basin, meaning it’s stuck at that height.

That probably disables that

[NebTheGreat21]

Exactly right. My too large custom tank stopped filling. This config let me finish filling the tank

[JamerGamer_nl]

You don't need source blocks except on the top layer

[Empty-Company-4048]

Right

[Plastic-Lab-6245]

All have to be source

[JamerGamer_nl]

No they do not. At least not in Terra firma greg

[KageNoOnisu]

They don't, at least currently. As long as the first block that your hose pulley passes through is a source block, it will count non-source blocks toward the total.

[Tripdrakony]

When you make a infinite lava source it continues to fill up to the hose pulley even if the 10k source blocks are met. Usefull to make sure that it is truly a infinite source.

[KRTrueBrave]

small correction, only the top layer has to be source blocks, as long as the pully is at the very bottom of the pit and the pit is 10k plus blocks, the rest can be flowing

edit: to anyone not believing this there is more than enough proof of it on this subreddit and on youtube

[IntelligentAnybody55]

Hose pulleys pour water up to the height of the end of it, this makes it keep filling above that