That does not look good. A lot of headspace for a secondary, but three days is to quick for an infection to have started in the secondary. I would say the contamination was in the primary.
if it is infected, be prepared to toss your primary vessel if it was a bucket, as well as all your transfer equipment. Or else youll pass it along to the next batch
the idea is that anythign plastic gets easily scratched, even if you cant see it. Those scratches harbor bacteria and are near impossible to clean out even with good sanitation practices.
Glass is different. But I replace my plastic gear every 40 or so batches anyway and do a hand-me-down of the transfer equipment to my brett then my sour equipment. Its not worth the time and effort spent to risk it to getting another unintended infection
If you can do a full volume boil, just boil enough plain water to fill your HDPE bucket to the brim and snap on your lid. Leave off the airlock so it can take in air as it cools. Let the fermenter slowly cool to room temp. Then clean and sanitize as normal. That should take care of anything that might be living in the bucket.
Edit for clarity: Dump the water into your bucket while it is still boiling...
It likely won't take even 140F, let alone boiling water. My local LHBS also does Black Box Brewing, & cleaning with 140F PBW warped the better bottles. So I'm not sure buckets can take much more?
It likely won't take even 140F, let alone boiling water. My local LHBS also does Black Box Brewing, & cleaning with 140F PBW warped the better bottles. So I'm not sure buckets can take much more?
I think HDPE buckets start to get pliable around 180F or so but can take boiling temps without deforming (unlike better bottles). I think it's pretty common to boil wort in a bucket with a heat stick in the UK.