Cutrine granular could kill fish eggs and pre-swimup fry if enough was applied. I do not know the dosage required to kill eggs and fish fry. Some, as much of it, would depend on the alkalinity of the water. Copper sulfate in rock salt size and maybe course fertilizer size (small) would work better than fine or powered CuSO4 because the CuSulfate is not buffered like Cutrine and more reactive and more toxic. Both algaecides tend to be more toxic in lower alkalinity water. The lower the alkalinity the more toxic the copper becomes.
FYI LMB are more resistant to copper than BG, BG more resistant than CC, CC more resistant than FHM & grass carp. Most sensitive are trout. Thus resistance to Cu from low to high: trout, minnows - goldfish, catfishes - sunfishes - LMB as most tolerant to copper toxicity.
Last edited by Bill Cody; 02/24/18 09:58 PM.
