tuxedo urchin spawned
 

My urchin spawned the other day when I turned the pumps back on after feeding. I thought something was wrong with him at first. Clouded up the whole tank. I was a little worried about it polluting the tank but didn't really notice any effects when I tested the next day. Did a good size water change anyway. Makes me wonder how many times he spawns that I don't see it. I would have to think it adds a pretty good bioload to a 29g system.

in this paper, Levitan (1988) observed monthly natural spawning in Diadema antillarum.

Urchins are readily induced to spawn via injection of potassium chloride (KCl) in the laboratory... sudden changes in aquarium conditions might achieve the same.

It is an interesting question... what's the impact on your water quality. Hopefully your skimmer can take out most of it as the gametes deteriorate.

http://bio.fsu.edu/~levitan/publicat...ology_1988.pdf

I noticed no increased skimmer activity. I put in carbon to help it out but noticed no increase in nitrates 24 hours after the spawn. Was out of nitrite tests. I read that corals like it as food but I really didn't notice anything changes at all other than the cloudy water which was clear by the next morning.