GPH is 550.
I really thought I was at the end of cycling, as I have been dosing with Ammonia and getting readings of 0 Ammonia, 0 nitrite, and about 20 Nitrate. I was actually going to move my fish over tomorrow. I noticed the growth right before/as I was doing a water change. I was going to dose again tonight, test tomorrow, then move, pending his results again. This will be 3 days with Ammonia being processed effectively.
I'll keep an eye on the algae and if needed, I can run up and buy the erythromycin.