Selling Tank, Need To Clear It Of Snails First!

[mbeer21]

I've been running my 120L for around 5 years now but I've decided to downsize back to my first smaller tank.
 
I've decided to try to sell the big tank, but it's got a big 'family' of Red Ramshorn snails living in it.  Is the only way to make sure it's snail-free in order to sell it just to empty it completely and throw the gravel away?  It seems a waste, but I know how badly dead snails smell, and picking them all out individually from the gravel would be a pretty big task...
 
The other thing - it has some big anubias and amazon sword growing on driftwood that I've had for nearly as long as the tank; I want to keep one of these for the smaller tank and sell/give away the other, but don't want to bring any snail eggs along with it.  Is there a way to make sure there are no eggs without killing the plant?  Or should I just start completely fresh?
 
Tank pictured below - all the little dots are snails.  (there are 6 fish in there too, they're just shy)
 

 

[StevenF]

s the only way to make sure it's snail-free in order to sell it just to empty it completely and throw the gravel away? 
 

 
Put the gravel in the oven.  at a temperature above the boiling point of water bacteria, algae, snails and eggs will all be killed.
 

The other thing - it has some big anubias and amazon sword growing on driftwood that I've had for nearly as long as the tank; I want to keep one of these for the smaller tank and sell/give away the other, but don't want to bring any snail eggs along with it.
 

 
For the plants you could take them out and dip them that will kill animals.  You could dip them in ammonia.  Plants have a higher tolerance of ammonia than animals.  
 
another option (I don't know if it would work) would be to remove the fish and slowly add Ammonia.  Since plants need nitrogen they should be able to tolerate levels the would be stressful and maybe even lethal to the snails.   If the snails start moving in mass toward the water surface where oxygen levels will be higher and ammonia levels lower only add enough ammonia to maintain the levels.  you could easily crush them when they reach to water surface. if you hold those levels long enough you might kill most of the snails in the tank   Do a big water change and let the plants recover.  After a time some of the snail eggs will hatch.  Add Ammonia again.  and repeat.  keep doing that until you see not more snails.  

 

[Baccus]

Ramshorns are easy enough to kill in gravel, but it means removing the gravel and leaving it in the sun for a few hours (longer if not days for MTS), sadly this sun treatment will also kill your beneficial bacteria that are living on the gravel. But if your other tank is already cycled this shouldn't be a problem when you go to add the gravel to it.
 
Removing snails off plants and timber is going to be more difficult, especially if you don't use any snail killing commercial treatments like snail rid, because the plants are going to be with shrimp at a later date. You could remove the plant and using a hose or tap with strong pressure blast any snails off that you can see. If the plant is attached to some wood or rock you can even tap this on the ground and ramhorns will fall off, I find they will even fall off with a good shake of what ever they are on. You could then put the plant and its wood/ rock in a bucket of water that you know is new water with no snails present. From there you can continue the blasting with a hose and swishing the plant in the water treatment over days to keep removing any more snails. Any time you see snails in the bucket you can tip it out, get rid of the snails and put new fresh water back in the bucket to continue the process 
Eggs of the ramshorns are going to be the biggest problem. Some eggs may get blasted off with the hose treatment, others you may have to actively hunt down and either scrape off or pluck the leaf off and dispose of it in the rubbish.
Adding ammonia to the water with the plants may work (snails hate ammonia) but plants love it and will gladly keep converting the ammonia into nitrogen for themselves, so it will be very hard to keep strong concentrations of ammonia up.