I've never had a problem with the aquascape epoxy (coralline algae colour) but hated holdfast as it didnt really hold anything fast or hold at all.
+1 I cant remember the brand I used for my tank, mind you I did let it cure for a week in the air before adding it to the tank. not sure if that saved the hassle or if its the brand.. now what was the brand....
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I'm not 'fallow' you must be talking about my tank!