Hi Jim
Just done my waterfall on my header pond, very similar to what are doing,I to have done mine in slate which is a dark grey colour,Like your self i did not want the black or white sealant,So i chosse a clear aquarium silcon sealant was ok for a couple of weeks then it started to come adrft and peel off.Ifound it did not bond very well to the hard surfaces of slate or stone.
After taking it all off i am now useing Polyflex-LM Sealant, which sticks to any thing especially hard surfaces which is flexible and also fish safe.Very good sealant, Should have used this first time round, but you live and learn.
By the way Jim i forgot to mention it is only available in black,But will soon discolour once you get your water course up and running.
PS I have also heard the gold label sealer is also very good,But a bit more exspensive tnan the Polyflex.Both are available from most koi dealers, hope this helps and good luck with the water course.
Shaun.
Posted on Oct 18, 2005, 1:00 AM from IP address 212.50.160.44