If you use 2-part, just be careful that you dose the two components spaced about an hour (or so) apart. I didn't when I was dosing and it caused large portions of my substrate to solidify.
I started with 2-part then moved to a geo calcium reactor. I also dose kalk at night but that's more to keep the ph up.
"If you use 2-part, just be careful that you dose the two components spaced about an hour (or so) apart. I didn't when I was dosing and it caused large portions of my substrate to solidify."
You shouldn't be having that issue if you have enough flow in the tank. I dosed 2 part for over a year and always dosed one right after the other. I dosed right in front of the power head.
Two part is easy and cheap. I use a reactor now due to system size and once you have it tweaked it doesn't get much easier. All depends on what you're keeping and calcium demand...