Having Caput Algol in your 4th house does not mean anything unless the star is conjunct or opposite one of your natal planets or house cusps. A fixed star has no effect unless it is conjunct or opposite a planet/house cusp with a 1-2 degree orb.
A grand trine is when there are three planets all trine (120 degrees) from each other. Not everyone has a grand trine in their chart. To find your elemental make up, look at the element each of your natal planets are in. For example, if you have a lot of planets in fire signs like Leo and Aries and none in water signs like Cancer, you will have more fire in your soul than water. Most people have one or two elements that are dominant. Elemental imbalances can be corrected by invoking the lacking element and affirming something like, "The ______ element is permanently balancing my soul in a healthy and positive manner for me."