I would be open to any suggestions you may have about different types of copper products or even other alternatives. I have looked into buying some of Hanna’s test kits but honestly 50 bucks plus shipping is a little steep for a single test product (But with it giving you a number rather than a color and a bad color chart is supper nice). And personally I’m not a fan of API test kits but it’s all I could find any of my LFS. Right now I am using RedSea test kits an am loving it.
If you are asking me about options for treating ich/velvet and the successful eradication of the two, here is my opinion.
If you are treating ich, hypo salinity and the TTM are less harsh options. Neither of which require a test kit (Hypo requires an accurately calibrated refractometer). Neither of these methods are "easy" to perform and require a lot of effort and strict procedures/monitoring.
The easier of the two (the only 2 if you are dealing with velvet) options are CP (Chloroquine Phosphate) or Copper.
CP is often difficult to obtain, as is should only be used when obtained with a RX from a vet. This medication is dosed by weight and is a powder form so there is no testing or monitoring.
CP is known to be harsh on anthias, blue hippos, and wrasse etc.
This chart may also help you in the future. It was put together based on experiences of several members here and the harshness on specific species using the above/below discussed methods of treatment.
https://www.reef2reef.com/threads/fish-and-treatment-guidelines-with-chart.283450/
Chelated copper seems to be the "easiest" on most fish when copper is being used.
In regards to copper, The main types we use in the hobby are chelated and ionic.
Copper Safe and Copper Power would be the most available forms of Chelated copper.
Cuprion and especially Cupramine (Cupramine seems to be the most widely available form found in LFS from people who are in emergency situations) would be the more common you see available for ionic forms.
The hanna checker will accurately measure all forms. IMO for $70 (Tester and spare pack of reagents since it only comes with 6) its well worth it, in the fact that if it saves you one or two fish each batch it pays for itself quickly.
It will also measure copper sulfate pentahydrate as well.
In regards to visual tests, most people tend to overshoot them with the uncertainty/inaccuracy of a visual test to make sure the therapeutic level is maintained. This is where the problem of overdose and fish loss comes into play. It is also very tough to monitor any absorption with a visual kit.
For visual methods of testing: If you are using chelated the API Kit is the proper kit, if you are using ionic the seachem kit is the proper kit.
Hach and Chemetrics make professional (Better than the 5-10 dollar hobby grade kits) visual test kits that may be easier to read, but they cost more than the hanna checker, so if you are on the market for something better than the hobby grade kits it doesn't make much sense any more to purchase either of them IMO.
All of this being said I am currently using copper power and the below dosing ratios with very much success (I use the 1.75ppm target) Safely above the therapeutic minimum of 1.5ppm but not high enough to encounter any copper sensitivity "yet".
https://www.reef2reef.com/threads/ratios-for-dosing-copper-power.385871/