You mean like this?
Did a test on it for the last 2 days, with dolomite in there just to see if it clouds the water and if it will stay running oh and water tight. Pasted the test, it will be working on one of my tanks this weekend. I have modifide it since that pic though. The bottom now has an inverted 2L coke bottle top siliconed to it. Shaped like a funnel so all the kalk will hit the spot the input sits at and there will be no dead spots.
Clinton