[Fishyfish11]

I know it's a long shot that you'll respond since this post was created so long ago, but can you tell me what you mean by "improperly installed?" We are having the same problem and I'm losing my mind.

Thanks!
Brad

[speedball1]

Hi fishy and Welcome to The Plumbing Page. At AskMeHelpDesk.com. You're responding to a 4 year old dead thread so I gave you one of your own. Look in then upper left hand corner of the first post form the date in the first post before you post, Thanks

can you tell me what you mean by "improperly installed?"

Sure will! Just as soon as you copy and paste what you're talking about.
In case you misses my earlier post here it is again.
I had drain flies in my shower so I realize what you're going through. A trap or bleach won't stop them. The following may help.

MOTH OR DRAIN FLIES

Moth or drain flies are small black flies which
Thrive in drain pipes and sewer lines. They need
A lot of moisture to complete their life cycle.
Drain flies do not fly well. They tend to drift
And seem to float along more than fly. Their
Wings are shaped like a leaf of a plant and one
Can see hair like fibers on all parts of their
Body which is why they are also called moth flies.
I have dealt with drain fly infestations in
Many homes which start in the sink or bathroom
Shower. The drain lines which have the most
Activity seem to be the ones most likely to have
An infestation. I have also observed that homes
With septic tanks seem most likely to get them.
I am not sure if there is some kind of build up
Which occurs more with this type of drainage
Or if there is something in the tank which allows
These flies to prosper. Although these homes
Seem more likely to get drain flies, once the
Cycle begins it takes place in the home. I have
Encountered several infestations where the larva
Were found crawling out of shower or bath tub
Drains. The homeowners thought they were some
Kind of leach. In fact, the larva of drain flies
Thrive in a slime buildup which is on virtually
Any drain pipe which is used a lot. This slime
Enables the eggs which are laid to be protected
And sheltered. The eggs and hatching larva
Embed themselves in this slime so they don't wash
Away. The cycle of these flies takes around
A month to complete. Don't waste your time with
Bleach or other cleaning solvents. Showers and tubs
Which have ceramic tiles may also supply a moist
Slimy environment in which they can live. Sump
Pumps and wet crawl spaces are other environments
Where I have seen them live. Drain flies can be harder
To control than other small flies. Although
There are several products to kill adults, the
Key is maintaining and minimizing their breeding
Areas. This could prove to be difficult and
Ongoing.
Like most flies, there are several products
Available for their control. Use a "SPACE SPRAY"
For immediate relief of the adults. There are
Several to choose from in the section below.
This will quickly control the adults, but the
Secret to getting rid of them is to use a
Product we sell which removes the slime build
Up on drain pipes. By removing this slime, the
Larva cannot develop. This will stop the cycle.
In the "SURFACE SPRAY" section below, look for
The product called SURVIVORS. This is applied
Down drain pipes and will remove the nest sights
These flies need. You may also use the product
Called PT-CYKICK which is located in the same
Section. It is ideal for treating in cracks and
Crevices where these flies like to lay eggs. Such
Cracks will develop around ceramic tile, windows
And grout joints.
Good luck, Tom