Re-using pots - how do you sterilize?

[Fairorchids]

I know that most use bleach to sterilize old clay pots. However, I wonder how effective that treatment is?

I have seen one grower stack old pots in a large plastic tub, add a gallon of bleach, and then fill up with water.
That tub probably holds about 20 gallons. Assuming a regular bleach (6%), that means:

• we are down to 0.3% concentration.
• provided that the bleach was fresh, and not deteriorated sitting in the bottle.

Even though he lets the pots soak for 2 weeks (with bleach evaporating/breaking down), I am wondering whether this is adequate to kill any virus particles in the pots?

My personal preference, is to scrub the pots, so they are clean of any plant material, and then bake in the oven at 425F (abt. 210C) for 2 hours.

Does anyone have solid scientific data on concentration & soak time required?

[DirtyCoconuts]

i like the old, put them in the soaking tub part of my swimming pool for 1-infinity months and then take out as needed.


i really do this and don't do anything else...if there is any staining and i want it off i get the pressure washer or the wire brush and its a short chore

[Keysguy]

Everything I've read says you can sanitize (not to be confused with sterilize) with a 1/32 solution of bleach to water. So, if my math is correct that's 4oz of bleach/ 1 gl water and you'd need to wet soak for at least 10 minutes.
So that means your friend was doing a 1/20 ratio and was soaking for overkill probably.
Having said that, I'm also doing plastic and not clay which is porous and would require stronger and longer treatment. And baking out will definitely assure you're good!

[thefish1337]

scrub with soap then immerse in 10% bleach for 10 minutes. rinse off and air dry.

[Ray]

Bleach does not break down in the bottle. It's primarily a sodium hypochlorite solution, so unless it is contaminated or you let the water evaporate, nothing happens.

[JScott]

We had a sanitizing dish washer, so I just run them through that. I think that should take care of it, although I could be wrong too. But I don't reuse pots very often anyway.

[Fairorchids]

Ray, this is from Chlorox web site:

Some quick background: The sodium hypochlorite active in liquid bleach naturally degrades into salt and water in the bottle. The major factor determining the rate of decomposition is temperature. The higher the temperature the faster the active is lost; older product also decomposes more rapidly. We even compensate for this by adding more bleach during our summer production. Generally, we say that under average storage (~70°F) conditions, bleach has a 12-month shelf life.