Should I wait until the water hits a certain temperature?....

It is approx. 60 degrees here in Pittsburgh....

But, the pond temps are around 52.....

Can I put: Water Lettuce, Water Celery, or Hyacinths out there, yet?...

Please advise...

Thx,
Ginger

You can put out the water celery now. Don't put out tropicals like water hyacinth or water lettuce for another month until after the last frost danger is past. Did you overwinter those succesfully indoors or just buy some recently? If you overwintered the water hyacinth and lettuce, please share your secret. Thanks.

Nope!!! <_< ... Not that fortunate.... The ones I did manage to save, the indoor creatures ate B) .... So, I ordered some more.....

Water lettuce cannot go out yet?..... Is it a tropical????

Thx,
Ginger

Yes, water lettuce is a tropical. Most pond stores won't ship tropical plants until the danger of frost has past.