Per gallon it varies per tank due to some having more things that consume more phyto than others.
500g (562g actual) = 9.6 ml per gallon per day.
180g (214g actual) = 7.5 ml per gallon per day.
75g (81g actual) = 1.6 ml per gallon per day.
40g (44g actual) = 3.1 ml per gallon per day.
14 bio cube (9g actual) = 6.5 ml per gallon per day.
one thing to not forget is the concentration of phyto being dosed. I have no idea how to tell how much, so to speak, outside of color. I dose mine before it gets the super dark green. You also have to account for the salinity being added in when you dump as much as I do into tanks. I use dosing pumps, controllers and salinity probes on all but the 14 to keep it in check. The 14 is palys, Xenia and a pod farm lol. Luckily it is not much of an adjustment on any of the tanks except the 14. My son enjoys this hobby so he checks it daily and adjust accordingly. For the other tanks, Skimming wet pulls out SW, ATO adds fresh, and the controllers do the rest. Before the controllers, the swing had to be checked manually and it was a pain. There were numerous times I went to almost 1.030 when I started to get up there in amount dosed. Slowly moved up to that salinity, but still something to think of.
In short, it can be a huge pain in the rear sometimes when starting to work towards a set level and figuring out salinity increase, evaporation, average of water pulled out by the skimmer and such. But I enjoyed the challenge.
Another thing to note, is phyto can culture in your tank. The 500 seems to be doing that and I am going to have to cut back on the amount dosed. Granted, not as much culturing as when done in a controlled environment, but again, an aspect to pay attention to.