Terry, what is wrong with the advice we've been giving you? Between Josh and myself I thought we had done a pretty good job of explaining what we think it going on with your scrubber but I keep seeing you post in multiple places with the same question.
There's a lot of missing context in this post, so you're apt to get advice that doesn't account for the issues we figured out after diving deeper into the discussion with you on FB.
Just so everyone here has this context, I can summarize it:
His tank is a clownfish harem tank with I think 30+ clowns (correct me if I am wrong)
Feeding is dry pellet food on an automatic feeder - and because clowns in a harem will get aggressive when underfed, they are well fed
He had the scrubber running for ~3 months but had never cleaned the screen
I can't recall the photoperiod but I think it was around 9-12 hours
We advised him to start regularly cleaning the screen every 7-10 days or so, but not to overclean. Having a screen run 3 months without cleaning could mean the screen might take a bit to bounce back after the first couple harvests, so it's a mature screen but not properly maintained, which is kind of an inbetween stage.
We advised him to bump photoperiod up to 18 hours. He definitely has the bioload to handle 24/7 but it's better to proceed with caution for a couple of growth cycles to make sure the screen is fully mature.
We did not address flow, but that really shouldn't matter too much at this point. As long as there is enough flow to fully cover the screen with water, that is fine. I am assuming that he is running the water 24/7 (I have encountered a few people who shut both lights and water off, which of course leads to issues quickly...so I don't think this is the case)
Make sure to clear the slot on the pipe of any growth when you do your harvests, as well as the top edge of the screen. This ensures you will have consistent and even flow throughout the growth cycle.
Regarding nutrient levels, at this point these numbers as it relates to the judging the effectiveness of the scrubber and the need to get a larger one or not are not relevant due to the past operation of the scrubber.
@Terry DeMott You need to allow the scrubber to fully mature and go through at least 2 months of maintenance to verify that you are getting at least somewhat consistent growth and consistent harvests. Combine that with testing results and then you will have a more accurate set of information that you can use to make further adjustments or make a decision about what to do, but only at that point does it make sense to do so. You do not really have valid information right now to do that.
One thing to also note is that when you perform your tests can make a difference, depending on your system. What I mean by that is, for your system in particular, when you pull out the screen and harvest the algae, if you harvest too much and your screen is relatively bare of leftover algae, you might see a bump in nutrients over the next day or two until new growth kicks in and takes off. So keep that in mind when you log your tests.
This is why I recommend a "lighter" level of harvesting/cleaning for you, you will want to leave at least 25% of the growth on the screen during each cleaning/harvest. What I do is scrape the screen in a diagonal "X" pattern on each side, or a grid or "#" pattern on one side instead of an "X" pattern. What you do not want to do is scrape all the growth off completely off of both sides, because this will result in a nutrient bump - this is especially the case with your system as you are feeding heavy with a relatively "dirty" food (dry pellets are generally high in nutrients).
Also remember that there is the phosphate leeching issue with your Pukani rock that we discussed several years ago. I'm not sure this isn't still part of the problem. As I recall, you still have that rock.
More than happy to help so if it works best for you to post updates here instead of FB, do that. It works better for me. Easier to keep track of in a dedicated thread instead of having to search for it
