The Doc is right. This stuff is cheap and powerful, a bottle will last for years (or turn to muck first).
It is relatively safe and tough to burn with, as long as you remember this:
1. Only about half of it's nitrogen is readily available. That means one feeding can last a month....depending on the size. This stuff WILL sneak up on you if you abuse it, wait until she tells you she needs food again.
2. This stuff is around 4.5 ph out of the bottle. It is stabilized there to prevent bacteria from growing and causing the contents to slither away.
Be careful, check ph, dilute very well, make a tea....whatever you have to do, but be aware. There are more tea recipes in my journal. I actually don't use this stuff anymore I use fish meal but it works just as well and is easy to find.
3. By itself it is painfully deficient in P and K, and most soils are too. It goes great with kelp though.
4. It is a nice form of sulphur, which plants need.