Low water pressure and slimy build up in faucet screen
 

Have a well and have increased the pressure on the holding tank under the house. It helped with some faucets but not others. I also just had a tankless hot water heater installed and hot water is running slower than cold. Third floor faucets have a slimy build up in the little screens. Any suggestions on where to start first?

ok
 

Sure do, You need to have a water quality test done to see what it is made up of, and what the PH turns out to be.
Then go from there.

That's good advice there. I didn't even think about getting a test done. That should definitely be your first move.

water pressure can be tricky as many factors can contribute to the overall picture.
What is your gpm flow before and after tankless? There is a manufacturer specified range that unit will work best with also unit may be clogged. Scaling can build on interior heat exchanger surfaces and constrict flow volume. Other factors apply but more information is needed.

Jonas Clark
US Trenchless

I'm waiting for the results of the water test.

Could be as simple as the aeriators are pluged up on the faucets.

I agree. Chances are when the tankless heater was installed, the mineral build up on the pipes got knocked loose and plugged your aerators. This is a normal occurrence.