When you are dosing milligram levels of lanthanum chloride to dropout milligram levels of phosphate. What you mostly see left behind is lanthanum(iii)phosphate. If any calcium precipitated it would be milligram levels of calcium, magnesium, carbonates, and other hydroxides. Which would be even hard to see. Those would in turn dissolve back into tank water. Much like when you add sodium carbonate and you see the white cloud that disappears back into water. So if you have a 100L tank with 1ppm phosphate. That is .1 grams of phosphate. Even if you added whole dose all at once it wouldn't take out the .1 grams phosphate right away. I used one ball as reference for simplicity. You would have lanthanum salts floating around for a while as well. 18 milligrams of lanthanum chloride injection is enough to kill a rat. Aquatic animals are much more sensitive. Their instructions say 5ml takes out 1ppm in 20 gallons. Its almost a 1:1 reaction so I assume one cap would have .195 +/- grams LaCl3. Dosed 20 ML like said earlier. That is about .78 grams or = 780 milligrams or = 780 ppm. That could kill 43 rats .186grams/20gallons LaPo4 after. Again that would depend on how long it takes to react with the phosphates. Much less than 780 milligrams over time but still possibly very toxic levels to fish.If that was the case you would not see the instant parcipation. Nore would it lower po4 at any dectable leval. There are thousants of balls as you refer to them in a much smaller area.