Bob - "expert"? Don't overdo it!
Weeds: CuSO4 (Copper Sulfate, "Blue Stone", etc.) will control many forms of contacted algae. However, the copper in CuSO4 has a tendency to rapidly bond with minerals in water, severely reducing its period of activity as an algaecide - since algae cannot absorb the bound copper. This mineral-bonding effect also causes the copper in CuSO4 to rapidly precipitate (fall out) to the pond's bottom - where it will become excessively concentrated after repeated use and cause problems with other organisms and natural processes that are vital for a healthy pond environment. From an ecosystem standpoint, CuSO4 isn't the friendliest of products (putting it mildly).
CUTRINE PLUS is a chelated ("kee-late-ed") copper formulation. The chelation process greatly reduces the necessary amount of applied copper, since none is lost to mineral-binding. Therefore, the significantly smaller amount of elemental copper in CUTRINE's formulation will provide more efficient and longer-acting algae control than the much higher concentration of copper found in CuSO4. "Longer-acting" is measured in days or weeks, depending on the dosage applied and the severity of the treated algae population.
With either product, the water's alkalinity will determine if the copper will represent a direct threat to fish. The lower the alkalinity, the greater the risk of direct-toxicity to fish and other organisms. Secondly, either product is capable of "indirectly" causing fish mortality through suffocation. If too much algae is treated at one time and/or if elevated water temperatures are low in dissolved oxygen, an oxygen-crash may occur due to the spike in biological oxygen demand (BOD) that is prompted by the dead and decomposing algae.
Your dosage question is well founded, and is very difficult to answer. You have obviously read the labels of both products - which is great. However, labels have their limitations on how accurately they're able to advise on "real-world" uses of such products. Technically speaking, the appropriate use-rate will vary according to the targeted algal specie(s) and its population density. You can achieve incremental benefit from multiple light-doses of copper, which is far better than using too much copper just once.
Without knowing any details regarding the various circumstances for your pond, and since I'm not familiar with treatment conditions in WI, I would suggest that you contact Applied Biochemist (the mfgr of CUTRINE, which is based in WI) @ (800) 558-5106. Optionally, you may want to track down a knowledgeable pond consultant or chemical supplier in your area for more assistance.
Appropriate preventative measures should be your primary defense against offensive levels of unwanted algae. Beyond that, CUTRINE is a much better option than CuSO4 for dealing with algae that cannot be managed through other means.
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Bill C.: you have probably been waiting patiently. Go ahead and expand on the above if so inclined.
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One more addendum: Here is an interesting site that discusses the characteristics of copper sulfate:
Copper Sulfate - Cornell