Originally Posted by MitchM (Post 980774)

There can be signifigant water chemistry changes including changes of the properties of surface tension to your aquarium water when doing a water change. It depends on the chemistry difference between exisiting water and new water characteristics.
I would turn off the skimmer for a couple of days after a water change if it is a problem.

Originally Posted by Myka (Post 980739)

Which skimmer? Have you measured water depth?

Originally Posted by e46er (Post 980716)

nothing has changed in the last 4-5 years apart from the skimmer. i use prime
just salt and i test the first batch and adjust the ca/alk / mg as needed. i roll the bucket first to mix it up, same chems Ive been using for years. last time I ordered a batch was probably a year ago but i use them in my dosing and nothing is out of wack. 55Gal plastic drum Ive had for 6-8 years, clean it out id say every 6 months.
my vertex in180 never had this issue. im just dumbfounded what would cause this. the skimmer neck is also clean.

it runs just fine for weeks i shut it off do a WC and 15-20 min later it wont stop overflowing

Originally Posted by clermont (Post 981526)

Prime will do it. I have used Prime exactly twice and both times my skimmer went nuts for a couple days. Try your next change without and my guess is you will not have that problem.