# sterilization of wood/LECA/gravel



## Rain_Frog (Apr 27, 2004)

I will need to sterilize my tank's furniture for usage in another tank. While I can clean gravel easily by soaking in a mild bleach solution and rinsing thoroughly, it isn't a good idea for the wood and LECA as both are porous.

I do not have an autoclave (but is it necessary in this case?) 

I think if I put my LECA and cork in the oven set at 200-300 degrees F for an hour, that should be plenty of time to kill off anything in it.

Any thoughts?


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## littlefrog (Sep 13, 2005)

You can sterilize LECA with bleach. Just rinse it well afterwards. If the bleach can get in, the bleach can get out...

Cork is harder... Depending on the size and just how sterile you want it, you could try an autoclave (or pressure cooker). Dry heat is not a very effective sterilant. It will kill a lot of nasties, but not everything, at least not at 300F. But, dry heat is better than nothing! Aim for 375-400 (much higher and the cork will burn), and keep your fire extinguisher handy.


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## Rain_Frog (Apr 27, 2004)

You sure about the LECA Rob? I'm pretty sure its clay, which is porous. Not sure if it would absorb bleach and then leach it later.

What about if I put a piece of cork bark in a big pan of boiling water on my stove?


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## littlefrog (Sep 13, 2005)

Pretty sure about the LECA. Bleach sterilization is a pretty typical thing when re-using it for orchids. I really can't see how a solution could get in that then could not be displaced. It shouldn't react chemically with the LECA, so sufficient volumes of clean water will wash it well. 5 or 10% bleach followed by a few changes of clean water should be more than sufficient.

But, if you are worried about bleach, put the LECA in a cast iron pan (dutch oven?), and put it in the oven. Most ovens have a cleaning cycle, which gets scary hot. Run a self cleaning cycle with the LECA in the oven. That will kill anything, literally by burning it up. Won't work with bark or cork, of course.

I don't know about boiling cork. I guess the worst that happens is that it falls apart and you buy new cork.


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## Guest (Mar 11, 2006)

nasty, i can't imagine all the dried bleach leftover... we use this stuff(LECA) over and over and depending on how much you have, either use a large pot on the stove or a steel drum in a field and a torch, and boil it for about 45 minutes to an hour. the only reason we do it though is because of the salt build up from chemical hydroponic fertilizers. but i'd suggest peroxide regardless instead of bleach, it is very porous stuff.


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## audioandroid (Mar 13, 2005)

i never use bleach on anything...just boiling water. why chance it? odds are you could do nothing and be fine so why add to the problem.


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## Rain_Frog (Apr 27, 2004)

I use bleach all the time when I clean frog tanks/buckets/ cups/etc.

However, I rinse things multiple times, and from Ed Kowalski's suggestion, use chlorine remover near the end because it will help neutralize things as bleach is sodium hypochlorite. Carbon doesn't hurt either.

I used to use boiling water, but not for tanks anymore because I would think water that hot would crack the glass or damage the silicone.

For plants, I think I'm going to try Kordon's 3% potassium permanganate to sterilize plant roots.


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## Rain_Frog (Apr 27, 2004)

Rob, is that because dry heat takes an incredibly long time to reach a substance...similar to why a roast takes forever to cook (but so tasty) in the oven. Water is an excellent media for temperature exchange.

However, what about dried leaves? Chytrid is killed easily by thoroughly drying, but killing other stuff, I would think due to the amount of surface area that leaves have, (and you don't compact them) they should get hot enough to kill nasties. Boiling leaves I think would ruin their look in a vivarium.


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## John J M (Jul 30, 2021)

Not sure if this is the best place to post this but I thought I'd mention a few ideas for sterilization/sanitazation of vivarium components.

Sterilization
If sterilization is desired you can only accomplish this by autoclave which is pretty much identical to a pressure cooker which is the home version. Requires time, pressure and moist heat and this will kill even spores if you're that concerned.

Sanitation
Next is heat. Moist heat is superior to dry heat like baking. Boiling or steaming are the easiest methods. But I'm not going to go into detail about time and temperatures. Microwave ovens can also work but be advised that they don't always heat evenly so some parts may not reach the critical temperatures needed. Plus microwaves can alter the composition of materials like the way bread reheated in a microwave will sometimes get hard as a rock. Personally I believe boiling or steaming to be the best. Dry heat the worst.

Desiccation or drying can work and is similar to dry heat. It can work but may cause some organisms to sporulate. Sun drying has the added benefit of UV irradiation which also kills.

Chemical agents can work as well. Bleach is best because it chews up organics and will probably even kill spores given enough time but I don't know this to be fact. It is inactivated by sunlight or dechlorinating chemicals easily. Besides bleach in liquid form one could use chlorine pool tabs in a sealed container for gassing. 

Another way is with CO2 gas that's heavier than air. Some people use dry ice but it's much easier to use vinegar in a jar and dump in sodium bicarbonate to generate carbon dioxide gas. 

Potassium permanganate is another great agent that can be used on bare root plants. It's available in most hardware stores and like chlorine, it also degrades organic matter so may kill spores. But I'd be willing to bet that a short exposure to frogs at the right dose would get rid of ectoparacites although I'm new to frogs and I don't know if they can get flukes. It is used with fish successfully but if too strong and too long it can kill them.

So if any of these methods interest you I'd recommend finding details about how to safely use them for your particular application. Hope this is helpful to you. I am new to dart frogs so I've got much to learn but I've already found many threads on this site very helpful and so I wanted to return the favor and my appreciation to its contributors. Thanks.


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## John J M (Jul 30, 2021)

Forgot to also mention freezing as another thermal method. If you have a sufficient large freezer chest or live where winters can be brutal, you have another means available to you providing what you're trying to eradicate cannot survive freezing. Unfortunately, most bacteria and fungi as well as many northern invertebrates have adapted to survival in freezing temperatures so you have to know your organism. Freezing is something that should be reserved for tropical hitch hikers and not for locally collected materials in northern climates, as these are most likely evolved to survive freezing conditions.


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