there are other soils you can use but I prefer light warrior and am going by what I know. talk to your nurseries and ask them what soil they have that are good for seedlings or what might be very low in nutrients (they don't need to know what you are growing).A hot soil is a soil which is high in nutrients(nitrogen being the one doing the most damage on seedlings). your hot soils usually contain some sort of guano(bat shit, worm shit, seagull shit etc....). I do not recommend a hot soil for seedlings. its better to be safe then sorry. you can always add stuff but you cant take it out unless you flush it and to flush it as a seedling is just crazy. You should be as gentle to your seedling as you can. there only going to be in the low nutrient soil for 2-3 weeks. just make sure the soil you get will dry easy because if it holds to much moisture, it will get stem rot and die