Question
This is not a question but a comment. I will try your suggestions on both covering the drains and segregating the plants to a room. I will see how it goes and get back to you. Again, thank you for the suggestions and the quick reply.

Answer
Ok, thanks. I'll wait for the results of the "experiment". Another way to tell drain flies from fungus gnats is to look at them with a good magnifying glass. Drain flies are covered in scales and look like tiny moths whereas fungus gnats look like tiny, black mosquitoes.

Jack DeAngelis