Thx for the extra info...much appreciated. This tub is only 5 years old (just off warranty) so I'm not really expecting problems with the tub structure itself...plumbing perhaps. As well, the main #1 pump (that does all the circulating/heating) has been replaced this past year (on warranty, thankfully) but perhaps a leak as a result of the installation. I'll check more carefully there. Right now, it's super cold here (-29C) so won't be doing any further checking till it warms up. Either way, I'll be ordering the product you've used and cross my fingers....thx again Cusser... :o)