I did also get the potassium, but forgot to list it. I had come across EI but honestly it felt like a trip back to chemistry in college and it didnt go well back then so it scared me to dive into EI. I figured the premixed was more expensive, but I do like the convenience of simply dosing with the pipette and not mixing or measuring anything. I don't have a ton of time for tank maintenance as is! I will try and do a bit of reading on it though. It seems like everyone is using it in this forum.
EI is actually pretty easy with dry ferts, but I totally understand it's overwhelming when starting the research. Some people make it more complicated by mixing big bottles of macros & micros ahead of time, but it's really not necessary. You can just use measuring spoons and dump the ferts right into the tank. I did that in the beginning, but then started doing a daily mix so it dissolves better in the water. Each morning, I just dunk a plastic bottle in the tank, fill it about halfway, scoop my daily macros or micros into the bottle, shake it up, and dump it back in the tank. No solution calculations required. Just be sure to rinse out the bottle if you use the same one for macros and micros. All you need is the cheap dry ferts, which should last well over a year, and some small measuring spoons like these: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
For your 25g, I'd start with this dosing schedule and adjust as necessary (as an example, I made Sunday your water change day):
Sun: 50% water change, then macros (1/4 tsp KNO3, 1/16 tsp KH2PO4, 1/16 tsp K2SO4)
Mon: micros (1/16 tsp CSM+B)
Tue: macros (1/4 tsp KNO3, 1/16 tsp KH2PO4, 1/16 tsp K2SO4)
Wed: micros (1/16 tsp CSM+B)
Thu: macros (1/4 tsp KNO3, 1/16 tsp KH2PO4, 1/16 tsp K2SO4)
Fri: micros (1/16 tsp CSM+B)
KNO3 is your nitrogen source and KH2PO4 is your phosphorous source. They both also have potassium (K), but K2SO4 is what you add if you just need more K. CSM+B is your micro source. The only fert I really worry about testing for is NO3 (nitrate), because it can harm livestock in excess. So for the first few weeks, I would test nitrate every day and try to keep it below 40ppm. I don't think the fert NO3 we add is as bad for the fish as NO3 generated by waste, but there's no way to differentiate the two when testing, so just keep the level below 40. Since your nitrate is zero right now, your tank is probably clean and not over populated. But if you need to decrease the dose of KNO3 to keep the nitrates in check after you start dosing, you should then increase the amount of K2SO4 you dose so you don't deplete your potassium (the K you decreased dosing with KNO3 needs to be replaced with more K2SO4).
Also, I see you listed Excel on your dosing app. If you're running CO2, you don't need excel, except maybe to spot treat algae with an eye dropper. So you can stop spending money on Excel.