I had the worst aiptasia problem I had ever seen, much less experienced. I think my biggest problem was that my Pukani rock provided a wonderful place for them to spread and grow... I mean, my entire rockwork looked like it needed a shave. If you have only a few aiptasia, you can use Aiptasia X or save some money and make a paste out of kalk and use that (just as effective and many claim better). Personally, I've never used Aiptasia X but have had success with kalk. The problem is, you can't see every aiptasia and even though covering them in kalk or whatever does kill them, they often still spread. In my current tank, a 142 gal, shooting them couldn't keep up with the growth, which eventually got out of control.
I would start by trying to manage your aiptasia by shooting them and if they get out of control, Berghai will eliminate them (that's what eliminated mine). However, adding Berghai isn't like adding a sea hare for GHA. With Berghai, all you are doing is adding breeding stock. Berghai are prolific, and it is the plague of offspring that will destroy your plague of aiptasia, not the few you put in the tank. It took like 4 months to eliminate my aiptasia infestation with Berghai, but it absolutely worked. If you are only fighting 5 or 6 aiptasia, I'm not sure Berghai would even work. The number of Berghai you would generate might not be enough to find and consume a small amount of aiptasia. If you do go with Berghai, stop all other methods of aiptasia removal. Don't worry about how bad the aiptasia gets just let the Berghai do their thing.
Also, you might find a few to remove at the end, but it will be a minuscule amount compared to all of the Berghai you have in the tank, and yes, they will all starve. If you need solace, I'm convinced this is natural. Even on the reef, it has to be common that patches of aiptasia are overcome by Berghai, most which starve when the food source is gone. Watching how they worked in my tank, when food sources decline, they start roaming more, even during the day. This makes them more susceptible to being swept away by currents, which on the reef, likely takes a few to new feeding grounds. Hence, most starve, but a few make it to a new food source, and the process repeats. I literally watched a Berghai blow around and land next to a lone small rock in the sandbed in the back of the tank, which was covered with aiptasia. A few days later, the aiptasia was gone. I also believe that there is a chemical release or something that draws other Berghai to a feeding site as I don't believe that one nudi, ate all of the aiptasia on that rock.
I would start by trying to manage your aiptasia by shooting them and if they get out of control, Berghai will eliminate them (that's what eliminated mine). However, adding Berghai isn't like adding a sea hare for GHA. With Berghai, all you are doing is adding breeding stock. Berghai are prolific, and it is the plague of offspring that will destroy your plague of aiptasia, not the few you put in the tank. It took like 4 months to eliminate my aiptasia infestation with Berghai, but it absolutely worked. If you are only fighting 5 or 6 aiptasia, I'm not sure Berghai would even work. The number of Berghai you would generate might not be enough to find and consume a small amount of aiptasia. If you do go with Berghai, stop all other methods of aiptasia removal. Don't worry about how bad the aiptasia gets just let the Berghai do their thing.
Also, you might find a few to remove at the end, but it will be a minuscule amount compared to all of the Berghai you have in the tank, and yes, they will all starve. If you need solace, I'm convinced this is natural. Even on the reef, it has to be common that patches of aiptasia are overcome by Berghai, most which starve when the food source is gone. Watching how they worked in my tank, when food sources decline, they start roaming more, even during the day. This makes them more susceptible to being swept away by currents, which on the reef, likely takes a few to new feeding grounds. Hence, most starve, but a few make it to a new food source, and the process repeats. I literally watched a Berghai blow around and land next to a lone small rock in the sandbed in the back of the tank, which was covered with aiptasia. A few days later, the aiptasia was gone. I also believe that there is a chemical release or something that draws other Berghai to a feeding site as I don't believe that one nudi, ate all of the aiptasia on that rock.