[Ganoderma]

You don't need to use a pressure cooker to sterilize your medium.

To clean/sterilize my hydroton. I boil 3-4 gallons of RO water on top of the stove. I place my hydroton (about 2 gallons total volume) into a 5 gallon bucket, which I pore the boiling water into and place a lid on the bucket and let sit for many hours, some times 24 hours. The boiling water will sterilize the hydroton and help to redissolve any salt build up on the hydroton. No chemicals needed, NO bleach needed.

[noreason]

Originally Posted by WHIPEDMEAT

phosphoric-acid, overnight usually, i don t remember exact dosage 85% the highest you can buy, and the ghe powder form ph down is also very good
bleach for disinfect, and the acid bath for adjust its Ph,without this Ph fluctaute a lot and wider spectrum disinfection if using both.. maybe too much, but better twice than none

Maybe I don't get something.

Disinfection and pH level are OK, but what about roots? I mean, this is the main issue when you want to re-use clay pebbles. Or at least this happen to me. I can't take old roots away and I can't re-use the medium with pieces of old roots, being a clean hydro setup.

So I would use a bath in a pure acid to decompose roots.

Being almost pure acid, a previous or subsequent disinfection should be useless. Pretty nothing can survive an acid bath.

The point is...when you talk about using acid how many liters of it for how many pebbles?
But...are we maybe talking about two different things?

Originally Posted by Ganoderma

You don't need to use a pressure cooker to sterilize your medium.

To clean/sterilize my hydroton. I boil 3-4 gallons of RO water on top of the stove. I place my hydroton (about 2 gallons total volume) into a 5 gallon bucket, which I pore the boiling water into and place a lid on the bucket and let sit for many hours, some times 24 hours. The boiling water will sterilize the hydroton and help to redissolve any salt build up on the hydroton. No chemicals needed, NO bleach needed.

Sterilize and disinfection, technically are two different things. You can't sterilize anything with boiling water (at atm pressure) but you're doing a good disinfection.
For example...few bacteria populations will die with boiling water. A big biofilm would not, need more time at high temp. or higher temp.





And for the crazy side of this thread...what about frying the hydroton in some kind of oil, carbonizing organic stuff (roots), sterilizing it with high Tº at the same time, and then wash it with soap?

[WHIPEDMEAT]

i try to write it step by step..

- pots with roots --> take them out shake it until you have only the stem in hand onto a foil, you have the LECA and some root mass, let it dry and with supressed air you can blow remaining roots out from it.

- now put all the hydrotons into a bucket or barrel anything, or just bathtube if nothing else you have to do the rinse and soak procedure

- there are other chemicals beside bleach like h2o2, isopropylalcohol depends on you what you like to use. after this, rinse it and let evaporate few hrs or overnight

- than the acid bath is set around Ph3-4 to soak it. i didn t measure it only the Ph value of the bath. it must be kept under 4 Ph, and you can let it soak for a while the longer the better, plus use an airstone to aerate it.

- build back your system fill it up with it, and run a few days before you plant anything into it with Ph 5.5 water on 0.4 Ec nutes

[Me2]

I use a rotating drum made of fine steel mesh. Dry the hydroton, throw it into the drum and rotate. The cascading, tumbing action cleans every ball and crushes any root debris into dust which falls through the mesh. Only take a couple of minutes. It works like a ballmill, except the milling media is the hydroton and the stuff being ground is the root debris. For smaller scale, you can use a steel fine mesh wastepaper basket for the drum.