Bio pollution mass filtering (space age)

[ufidlo]

Hi there,

I just wanted to share a creation of bio pollution filter . I was just sick of so much red pollution around the map.
I tried tree agri towers first, but they just don't do eat enough pollution to offset the output of biolabs researching.
Then I looked at biter nests (400 per behemoth sounds good!). But I could not make it work persistently.

After a bit of research I found this:
viewtopic.php?p=281727#p281727 (linked from https://www.reddit.com/r/factorio/comme ... ?context=3).

So the biter nest absorbs until it hits a internal buffer limit (3x most expensive unit at given evolution) and then it stops (that's what I've been observing). It must form sort of an attack group, which is not formed if there is not enough space around OR (!) if you kill the biters too fast.

But it takes just a little moment to make it work and absorb huge amounts of pollution! Just give the biters a step or two and that's it!

How it looks like:

02-14-2025, 20-20-31.png (76.9 KiB) Viewed 491 times

02-14-2025, 20-21-26.png (7.88 MiB) Viewed 491 times

Non-absorbing nest:

02-14-2025, 20-22-48.png (220.98 KiB) Viewed 491 times

"Pollution absorbed" is capped at ~1200 and stays there, spawning cooldown is -2, so it's blocked and not spawning.

Working (filtering) nest:

02-14-2025, 20-24-22.png (417.57 KiB) Viewed 491 times

"Pollution absorbed" 0 - 1200 and sometimes "pollution needed" spiking up and eating from that buffer.

So what I learned so far:
- nests "produce" from to the 2nd from the gap (inclusive), so that's why there's a gap every 4 nests. The structure is not symmetrical now, as it was an experiment
- nothing spawns if 7 tiles around it is blocked.
- the biters need just a little bit of time to live after spawning, the structure can be made way much smaller, you can even gate them in and let them wander a bit (put the turrets with a larger offset from the nest, but covering the walls
- it WORKS! (currently filtering out about 5k pollution/min from my base)

I bet you could even do a farm producing eggs and burning them to power the turrets

To verify your designs use debug menu (F4) and check "show-debug-info-in-tooltips" (and possibly install minimap disabling mod to actually see it). Then you will see the values on nests.

For the blue water!

PS: dunno if this is new, just wanted to share

[jdrexler75]

I just put some efficiency modules in a few beacons instead... and pollution goes down to 20%.