Thanks for your interest Mr. A,
The salinity does not vary as much as I expected during tidal changes, due to the fact that the bay has very little fresh water influx. Also I've not been looking at the parameters but a few years and we've been in a drought condition, so it hasn't rained much either.
Nitrates, I've measured as high as 20 ppm, but then the Bay is shallow and full of seagrass, so they probably absorb a good portion of it. Also Florida has very strict runoff laws, where all new construction has to have catch ponds to trap runoff. With very porous sandy soil, there's not as much runoff here as at other places I've lived.
The flux of algae growth on the rocks at the jetties is pretty dramatic during the course of a year. In the winter, when the water gets as low as 55d F., algae covers everything. All kinds, but mostly micro stuff.
As the water warms in the spring, the black urchins appear and slowly eat it all away, so that by July the rocks are mostly covered with corraline.
I've not measured phosphate, but will have to start looking at that.
One of my anemones spawned last night. Very interesting to watch. Over the course of an hour, it kept shooting out strings of white finely divided material, I couldn't tell if it was male or female, but since I could see the particles with my eyes, I figured they were probably eggs. Unfortunately it's the only specimen of that species I have, but I also noticed that the corals were extended greater than I'd ever seen them, so they were probably getting their fill!