My setup is a pretty standard 2" insulation-based raft trough system, using gravel as my media.
My question is for those who are using rafts, and re-usable media like gravel.
Do you clean and/or sterilize your rafts and media between uses?
I could see setting up a rack of some kind with a tub under it, and then spraying the rafts with a water/hydrogen peroxide mix, or a tray big enough to lie a raft down, and soaking them in a hydrogen peroxide solution for a few minutes, and then hanging them up to dry. Does anyone do anything like this, or do you just spray/scrub them clean with water?
For gravel, I could see again spraying a hydrogen peroxide solution on it, or, and I really like this idea for no good reason, building essentionally a tumbling composter. Get a blue barrel, hang it horizontally on a bar, drill holes in the sides, and then rolling gravel it in while spraying hydrogen peroxide, etc.
Or, I could see sending all the gravel through a worm bin, but that would be very labor intensive.
I only wash off dead leaves on the tops of my rafts and try to keep my top paint white. I will give the sides and bottoms a quick rinse to get any roots/leaves off. The bottoms are covered with beneficial bacteria and microbes. Sterilizing not only is very time consuming, but expensive if you are purchasing H2O2. It does not make sense to me to sterilize things that are part of this kind of ecosystem. We are relying on bacteria for the process to work so why would you want to kill it?? Sterilizing is for chemical hydro.
I will wash roots out of my seeding media and reuse it as quickly as I possibly can. The media is filled with bacteria and microbes that I do not want to loose. The quicker I get it back into the water the less beneficials I loose.
I was more worried about plant diseases that can stick around in the media.
When ever I have the choice I use disease resistant plant varietys. On the rare occasion I have a diseased or sick plants I remove them immediately and will scrub the raft a little extra and let it bake in the sunshine for a few days.
I agree with Chris on this one... if you have spent a long time building up the bacterial colonies in your growbeds then the last thing that you want to do is to sterilise it and have to then start again. You will find that it will be uncommon for plant diseases to stay in the media, and so you should have no problems with that - perhaps leave it for a short time in the sun just as with the rafts.
Do you clean or sterilize your netpots between uses?
I'm not worried about my bacteria colony. I also have gravel beds in this system, and am using gravel-filled sandbags to hold down the aeration pipes along the bottom of the troughs. There's plenty of room for the bacteria to grow, other then the bottom of the rafts.