Although this BP reactor is not on a mature reef as yours was when you initiated your BPR first time around (sounds like this is your second go at it) it is on a 2 yr old heavily stocked FOWLR system. My high levels of NO3 (25ppm+) and PO4 (.29) I thought would be sufficient enough to feed the pellets and kick them into consumption. I know that adding other bacteria is possible with MB7 and the like but I don't get the point of it given that I have a 'high nutrient' system from the start.
Ok.. Lol, first thing.. nice setup with your plumbing! Next, your system is obviously not nutrient deficient, so as you know, that's out the window. The next thing is that I run the 135 reactor(2nd time) on my 65 gallon system(ran it on my 110 previously).
Just looking at your video, I am with you in saying that your skimmer, something's not right if that's as wet as you can get it. I just decided long ago, since I'm running dynamics, I'm going to run "all" dynamics. I haven't had, or let me rephrase: I "have" had phenomenal results ever since.. I am running 18oz of the pellets in my 135 reactor. The system had only been set up for 2 months and I didn't start the pellets until 2 weeks after the system was up. So my system is very immature also. And my nitrate is, and has been at 0 for at least 2 weeks. But.. I have never had a problem kicking the pellets to go in about 6 weeks at the very latest. But then,I always started them with bacteria..
I soak the pellets overnight in salt water and mb7.And your question was why the added bacteria: well, you really want to get them on the surface as fast add you can. Yes, there is natural in the system, but think of the reactor as it's own little bacteria sees pool. You need the concentration up in there.. That's where it's important for the pellets..
But I don't think the problem is completely the pellets. I think it's part of it, from the standpoint that they haven't kicked in, and because your skimmer isn't performing for you, it's throwing doofus from the pellets, into the system, creating nitrate and phosphate.. Yada, yada..
So what do you do at this point? Well, what I would do is first, put the gfo and phosphate reduction back on. Keep your system up and running fully until it's ready to pull the extra off. Yours isn't ready yet imho. Next, because your running a recirc, you have a lot of flexibility. I like your tumble rate. But, you want to reduce your process rate(top blue) until the skimmer issue is resolved. Your gonna be dead in the water with much more than the pellets of you don't get that resolved. And during the break in of those, I only ever run enough water through it, to just get water through it and not be stagnant(you bought a great reactor, so use it to your advantage). Then, just for now, because your skimmer is giving grief, slow down the quantity of feeding or change types. It's only do much you can do, but slow the accumulation of nutrient. Then, bacteria suppliment for a couple weeks. It will jump start our either speed up your pellets. And you will certainly know when things are ready in the reactor. There is a drastic change in the skim.
But one thing you "have" to do is get either that skimmer working to where you can make a semi transparent tea skim, or simply buy another skimmer. If you go the latter, save yourself headache and just get a dynamics. All of the specs in the world honestly fly out the window with practical application.