Lol no like an overflow box , you can remove collection cup from skimmer and dose into the bubbles. My phosphate is back at .24 and 6 drops take me to around .15 (40b with 20g sump) but my rocks have alotn of phosphate binded it will go back to .25 the next day lolOkay, will do. When you say overflow, do you mean directly into the tank with an area of high flow ?
The only skimmer I have is a coral life mini skimmer.