Returning to the tank after 2 days, ostracods?

• pH:
• Temp:
• KH:
• GH: 14
• NH4:
• NO2:
• NO3: 7.5
• PO4: 2
• Iron:
• Dosing: 0.5 iron chelate, 25 mL Melafix, 2.5 ppm NO3
• NO3:PO4 Cumulative Dosing Ratio: 40:4.55 = 8.8

Notes:
I was away from the tank for 2 days. When I came back, the angelfish had laid eggs again. The angelfish were very aggressive towards each other, constantly biting and chasing each other. The female had damage around its mouth area and some loose scales on her body. To be safe, I will probably avoid dosing Excel for a day or two to see if there is any progress on the eggs. Until I see if the eggs survive or not, that means I also can't do my usual weekly water change. Since I hadn't been dosing Excel for the past two days, I could see some thread algae growing. An anubias flower also bloomed. For whatever reason, the hairgrass is still continuing to yellow slowly. The stargrass is growing normally, but its leaves are smaller than they were last week.

Those little water bugs also seem to be multiplying. They are swimming in the tank now. None of the fish seem interested in eating them. The harlequin rasboras will mouth them and spit them back out. I noticed that whenever I pour the Melafix into the tank, it gets sucked up into the AquaClear filter and kills some of the bugs in the filter, and the dead bugs then get poured out of the filter output.

These bugs might be ostracods, according to others on the forums. I had noticed that the side root hairs on the java fern roots had seem to have gone, leaving only the bare root stems, and I was puzzled as to what happened to them. One of the L. hippuroides plants also seems to have damage on its leaves that I don't think is due to a nutrient deficiency. It might be damage caused by these bugs.