Hey Erwin,
Since your BH is not leaking. I would leave the stand-pipe unglued. This will enable you to remove it for cleaning of pipe and your overflow. There really shouldn't be a problem with the minor leak since the return pump is usually running 24-7. Be sure to plumb a ball valve in the overflow drain pipe for maintenence purposes. Just another nickel's worth.......lol.
Scott
Thanks Scott,
got that covered. I think I may replace the coupling with another one. I found that the coupling I originally used had a tapered edge inside the section where the one inch pipe fits into. I found anouther coupling that does not have a taper in it.