Help confused!

I guess im confused lol i just got a couple of uv sterilizers for the first time and from what i understand to kill bacteria the gph should be 20-25 for every 1 watt and parasites 8-10 for every 1 watt...Then i read that you will have to choose one over the other either bacteria or parasites cause the gph will need to be diff for the two..its a 11 watt bulb so if its pumping threw say 100 gph to kill parasites wouldnt it still kill bacteria to ??? also is there suppose to be a way to adjust the gph ?? mine just says 150gph max and i dont see no way to lower it..................

Yes it will. The longer the water is exposed (lower the gph) the greater amount of parasites/bacteria is killed. If you can get the lower setting without dmg the light fixture you should be good.

Some of the new UV sterilizers are using the "twist" to increase GPH and keep exposure level long enough to kill parasite/bacteria/algae you name it.

I am using a 9 watt Uv with a powerhead built in so no adjustable flow...but it seems to be doing the job..keeps tank spotless and no sick fish

i got a 9 watt with the powerhead built in says the flow is like 220gph..and i have a jebo 11 watt with the powerhead sep...was thinking about maybe getting small canister filter and hooking it to it

Yes the longer the water takes to pass by the bulb the more stuff that gets fried.