Do you use GFO?

[danny zubot]

I run it in a phosban reactor and change it out every 4 weeks. In testing phosphate, I'm of the opinion that the GFO seems to be measurably effective for not much more than a few days, but I'm not willing to change it that often.

I'm estimating the effectiveness by measuring phosphate in the system vs. the outflow from the reactor. If there is a difference, then I assume the GFO is working. That difference seems to exist for only a very short time.

I think my algae is exporting phosphate much more efficiently than my GFO does.

Visually I found that my tank looks cleaner when I added the GFO, then slowly returns to its natural dirty state. Your testing sort of backs up my observations.