I am planning on using ozone as well and have done quite a bit of research on the subject. As for your question goes, it should be connected to the pumps ventury under the water at the pumps intake. Just a word of caution, you need to use tubing that can handle the O3 as it will erode the pipe in no time, you need to use a skimmer that can handle ozone and you need to place carbon (charcoal) around all the outlets of air and water to neutralize the ozone that it doesn't enter your system or pollutes the air with ozone as it is very harmful and can cause serious health issues. All and all it has a lot of positives and well worth it. If you can, rather look at getting a ozone reactor, safer and more efficient. Hope this helps.