[WolFoX]

I took a risk to start this topic and gather all my knowledge around the subject into a guide if I am lucky enough. I will be grateful if forum participants will involve in developing this thread with their knowledge and experience.

MAIN QUESTIONS.

• What temperature kills pathogens, attached to the aquarium equipment?
• In the case of UVC sterilization, how long time of exposure is needed?
• Is it a safe way to sterilize equipment in BOTTLE #1 with chlorinated solution (dip), BOTTLE #2 with clean water (rinse), BOTTLE #3 with an extreme dose of de-chlorinator (rinse) and straight to use in the next aquarium?
• Is Far-UVC same safe for fish, as it is (at least stated to be) safe for humans?
• What will be the fastest, easiest way to sterilize common equipment?

Spoiler: PRE-HISTORY

About 3 times I went through a global infection spread around all my betta tanks. I use the same equipment (droppers for food delivery, dropper pipette for sucking the poop, gravel cleaner for draining water, cups as temporary housing for fish while washing the tank, temperature meter, salinity meter, etc.). Diseases such as velvet (by Oodinium) and pinhole fin rot (Aeromonas???) are spreading at the speed of sound. Even if I put equipment into just boiled water for a minute or two, I am still seeing fish getting diseases one after another. This topic is a pain in the ass for those who accommodate more than 10 bettas, and I need help finding ways to prevent spreading things from a sick fish to those who are healthy.
With all my respect, I want to avoid comments about “if water quality is good, fish won’t catch a cold”. I do accept this phrase as correct! But there are much more parameters except for water quality that we can hardly control. Even in ideal water, fish still fall sick sometimes. Using the same equipment in breeder's farms is one of the way, that mess all things up even with good accommodation parameters.

WAYS TO STERILIZE EQUIPMENT.

「1」Soaking in hot water.

Found the article about killing waterborne pathogens that can affect human health. I think it may be more or less the reference for fish keepers too.
https://www.health.ny.gov/environmental/water/drinking/boilwater/response_information_public_health_professional.htm#:~:text=It is also reported that,in five minutes of exposure.

• One minute of heating to 162°/72°C and two minutes of heating at 144°/62°C for protozoans.
• 150°F/65°C for 5-20 minutes for basically everything.

But this way is bad for:

• Aquarium Plastics (pipettes, droppers, gravel siphons, tubes, etc) ⇒ they all as a minimum will deform and likely not come back to their original state.
• Hard plastics, such as measuring cups, and pipette droppers may crack after a few times, then spring a leak after a few more hot baths. A crack appears obviously much faster if right after a hot bath the equipment goes into the cooler aquarium water.

Thinking, if buying a mini cup heater will help me maintain a water temperature above 162°/72°C while I am cleaning tanks, so that I can dip equipment in that water for 2 minutes just to be sure. Sound like a load of time to wait.

「2」Bleaching the equipment.

The easiest way, but takes longer time and more money. Soak, rinse well, and de-chlorinate in a bucket. Impossible if I need to clean 20+ tanks in 1 hour one after another.

「3」UV Sterilization.

Any bulb, which works in the UV-C spectrum.

• UV-C or germicidal UV
• Far-UVC (It's believed to be safe for humans to be around)
• Broad-spectrum UV

The working dose is assumed to be 50.000 micro W sec/cm2 (don't remember where I found that). All bad organisms are dying under 45.000, but protozoa need 90.000 ⇒ so double the time of treatment. Therefore, if I have a dropper 25cm long and a bulb of the same or bigger length, then 2 seconds seems to be enough. Flip four times to eradicate on all sides, and I am done. Having kind of a UV box seems to be very useful to sterilize all objects after they have been in contact with water.
Is it really as easy as that?

I will likely edit the first post of this thread whenever someone will reply, or if I found something new in my current research.
Providing a link to the source of the material is advised.
Personal experience has no source, but any detailed information is advised (time of exposure, temperature, wavelength, etc.)