Are you sure they are red bugs? They could also be white bugs (some people call them grey bugs) or worse black bugs.
Red bugs are the easiest to see or notice with the naked eye. And they seem to be the easiest to eradicate. A good way is to use your phones camera to zoom in at night while you hold a separate flashlight with your other hand. The black bugs are tiny. About a third of the size of typical red bugs. White and black bugs require more interceptor.
I have experience with interceptor, and I usually do at least one proactive full treatment yearly to every 18 months.
I would not be worried about dosing the full tank with interceptor at all. I have also used the interceptor plus with Prazi, I would much rather the old school pills but the chews are fine, and I would also prefer the regular interceptor over the plus.
The standard treatment is 1 pill for large dogs (23mg milbemycin oxime) for every 400 gallons. I think this is way too low of a dose. This dose is for red bugs. The white bugs and more recent to the hobby black bugs take much more than the standard dose. I would consider 1 23mg pill per 100 gallons to be the standard red bug treatment currently. And I would go much higher for white or black bugs.
I have done 3 large dog pills per 100 gallons (my tank happens to be right at 100 gallon water volume) once a week for three weeks, with no ill effects. Everything was fine. Now I guess per the original formula that would technically be 12x the dose. However in my mind I consider that 3x the dose as like I said I go by 1 large dog pill for every 100 gallons. Using my method I would definitely prefer the regular interceptor as I don’t love dosing the tank with that much Prazi. However the last time I did the *12x I used the plus and the tank was fine.
The interceptor plus will obviously kill all crustaceans, and the Prazi will kill all bristle worms. Which some people like. I happen to not mind bristle worms so that is a negative for me. The Prazi will also deplete oxygen so I would remove the skimmer cup and let it overflow, which you should do anyways.
I also do not preform any of the typical water changes and use of carbon in between the three weekly treatments. I do the following. Week one, let’s say Monday night: turn off UV, remove skimmer cup, remove media from any reactors but let water flow through them. Dose tank. Wednesday I would put the skimmer cup back on, but not add carbon, and don’t do a water change. Then I would do the same the next two Mondays. The first Saturday after the last treatment (week 3) I would do a water change and run some carbon. I would also definitely recommend placing an order for some pods earlier in the third week. Maybe Tuesday/Wednesday of the third week so I have them ready. And I would spend about $100-$150 on them making sure I load the tank back up. Usually by the third week, people start seeing algae outbreaks, diatoms, and sometimes Dino’s. If any of these happen I would not do anything different. I would not start going crazy trying to resolve any of them. I would just give the tank, and pod population time to rebuild and things will settle back down in a few weeks.
