Blood Meal?

Well I was trying out my new pH/Lumen/Moisture reader today and my soil seems to be a bit alk. (7.5) which most people complain MG is a bit low on the pH scale.(5.5) But I found a huge box of Blood Meal in my house 12-0-0 that is supposedly very acidic. Would it be beneficial to my pH as well as plant growth to add a bit of this to my soil or water?

I was also wondering about a yellow color on my first sprouts leafs. Some are a dark green, but others struggle with one large healthy leaf and one small yellow one. Is this just because I'm using bag seeds? Or pH maybe? (Which I rechecked and is actually about 7.1) Or too much light/heat? (2 26w cfl + 2 13w cfl - about 2-3 inches from plant in a small box right now that is about 83F with fresh air blowing in) Any help?

Start with a very little bit and test the ph. You dont want to throw so much blood meal into the mix that it solves your ph issue but starts to nute burns the plant. I use general hydroponics ph up and ph down. It has a very low disolved salt content. Your temp and light is fine. With a cfl the closer you can get without burning, the better. Seedlings dont require much light. Most of their initial growth is hormonal. Its making a good root structure. This is why you want to go easy on the blood meal the first couple of weeks. I always like to give my seedlings a fighting chance. If the trend continues with the next two sets of leaves then I would ditch em. Its really difficult to find good genetics in bag seed.