First let me say I like Red Sea products, but I find Coral Colors to be difficult to use, and you have to be careful with generic dosing by calcium uptake. It is always best to dose based on testing rather than generic uptake recommendations. So, I bought the Coral Colors Test kit...not worth the money. Here’s my experience trying to determine what amount to dose.
I am very particular about testing, cleaning bottles, etc so I believe I am using the test kits accurately per instructions. For the Potassium Test, Red Sea gives me 426 ppm. The Salifert Potassium gives me 380. This has been repeatable over weeks. Since we want to keep Potassium around 400, I’m in the ballpark, but if I dose based on Salifert, I am overdosing based on Red Sea. Which is right? Same problem we have with many hobby test kits. I also noticed my potassium does not change much based on calcium uptake so it may not be appropriate to add Red Sea Potassium based on calcium uptake. That rule may only apply if you have a lot of corals that use a lot of potassium which I apparently do not.
I do like the Red Sea Iodine kit. When I tested with Seachems Iodine/iodide test kit, I got zero. Means I should dose right? When I test with Red Sea, I get .06 which means my Iodine compounds are at target and I should not dose. I originally relied on Seachem and added Coral Colors iodine. When my Red Sea test came it showed .09. Too high. It went back to .06 after some regular water changes. I have not seen it drop since. I stopped dosing it. After a month, it measures a slight variance, maybe .05. If I had dosed by calcium uptake I would already be back at .09 or higher.
Iron test is worthless. Testing for iron in Sea Water is very difficult. So much so that you have to call Red Sea support to learn that the test is normally zero and the only way to test is to add their coral colors iron and test one hour later to be sure you didn’t overdose. You have to call tech support to get that advice. Iron dissipates in Sea water quickly presumably turning into forms that are not detected with hobby kits. The test cannot tell you what your levels are and they don’t sell refill reagents anyhow.
I still like Red Sea products, but I stopped using the Coral Colors program. The only way I would use it is if I could get free weekly Triton tests to guide dosing. As it stands now I just observe the tank and enjoy it and my coral colors sit in the shelf expiring.
Sorry if this is discouraging to you, but I wanted to share my experience. I too would be interested in hearing how others use this product successfully...I don’t see a good way to do that.