I’d love to see the results of your test Gary. I incorporated a Kessil H380 horticulture Light over a small section of my sump. It’s only about 3-4 gallons. My total water volume is about 140G. I certainly don’t have 10x flow through there either. I’m not stocked very heavily but I’m slowly increasing my number of fish and I’m feeding pretty heavily. The Cheato is doubling every 10-14 days. My nitrates are zero and my phosphates are .001 by Hanna. This is obviously super low and not where I’d like it. But, at the moment it completely out competed a little caleurpa outbreak, and is doing some serious damage to a bubble algae dust up. So that I’ll take.
Anyway, I’d love to see what actual trace elements are being depleted over time. Tests are $50 correct? Bucket of salt, $50. So I don’t know.....