My advice was to replace the thing now with plastic as a good
alternative to
chopping down the tree.

I seem to have missed a few posts somehow (probably my attempt to avoid the
"junk" from earlier in the week) so did not get teh original of this.
However we have looked into replacing tank but can not afford to for several
years. Also the current tree is past its best and, in the opinion of
everyone who has seen it, probably was not ideal for the position anyway.

--
Hayley
(gardening on well drained, alkaline clay in Somerset)