does anyone here know how to sink mangrove roots as they are realy bouyant and i dont want to fix them to rocks or other heavy objects????????????

You could try soaking them in a bucket of water for a week. Stick a brick on top to keep them under the water. Hopefully they will become saturated and won't float. Exactly the same happens to driftwood after it has been out of the tank for awhile.

thanks i have been reliably informed (by smikeb) that i have in fact got red moor roots .......... any more takers on this problem of mine please ...thanks to all in advance

i believe you can't get rid of the sinker. any wood
that had been dried and out of water for a while
will still have buoyant force even if soak to water
for a month. what others do is to bore a hole on both
end or wherever you may want and put some concrete in
it. when dried, treat the cement with neutralizer before
soaking to the water for a week to remove concrete acid.
this is the only way you can sink the wood.

i sank my driftwood by putting it in a kiddie pool and placing a cinder on top of it for about a week. this got rid of most of the boyancy but still had to anchor it down in my tank for another month or so. this i did by screwing a piece of plexiglass to the bottom(be sure to use a stainless steel screw) and burying it in my substrate.

how about brass screws??

brass screws still get corroded although has a longer
span of life than ordinary screw. stainless do not react
to oxidation.