Rob, Rather than dose in the morning prior to a water change, try dosing directly after your water change. When getting a tank ready for competition I usually to a WC Mon, Wed, Fri and dose right after emptying. The extra circulation/agitation from refilling helps dissolve and distribute the chemicals better than the filter alone. Dosing right after a WC also maximizes the uptake time, ensuring I'm maximum getting nutrient uptake before the next WC. et al, Here are some numbers and a little math to help estimate your initial dosing concentrations when using dry chemicals. I've also found a gram scale sensitive to the first decimal place (0.1) to be useful because not all suppliers sell the same density/grain size substance. Using the scale find the average mass of 5 (or more) teaspoons to get the approximate amount you'll be dosing per teaspoon. Don't go crazy leveling it unless that's how you always dose. Get measurements of what you actually use for a tsp (be it perfectly level, tap-leveled, rounded, or heaping) when scooping out a tsp day in and day out. Example: I want to use anhydrous CaCl2 in my 60 gallon tank. The material I get is a very fine powder and 1 tsp is approximately 4 grams. That helps me estimate how many tsp it'll take to reach a desired target concentration. I've found this to be a very useful method (if a little more time/math intensive) for tanks 180 USG or greater where one is adding large amounts of of a substance. That being said, it does help the user to get a more accurate idea of how much you're putting in which is especially nice when trying to get help on forums. % ion in 100% pure salt (rounded to the nearest whole %)- KNO3: 61% NO3, 39% K KH2PO4: 70% PO4, 29% K MgSO4*7H20 (Hydrated Epsom Salts); 10% Mg CaCl2 (anhydrous): 36% Ca 1 gram of each substance will increase concentrations of X ion in 10 USG/37.85 Liters by % mg/L (ppm) assuming 100% purity. For example, 1 gram of KNO3 will increase NO3 by approximately 61 mg/L and K by approximately 39 mg/L in 10 USG/37.85 Liters. Using the Ca example above. I want to reach 20 mg/L Ca in 60 USG/227 Liters. 1 gram = 360 mg Ca so 1 gram CaCl2 in 227 Liters = 1.58 mg/L Ca. 20 mg/L (target) / 1.58 mg/L/gram CaCl2 [in 60 USG] = 12.66 grams CaCl2 powder. 12 grams / 4 grams per tsp = 3 tsp to get 20 (ish) mg/L Ca. The actual level will be slightly lower because the material I'm using is only 98% pure, but the concentration is still more than high enough to be non-limiting.