How to breed your own beneficial microbes
What they are suggesting is: It makes nutrient uptake a more smooth and easy process for the plant, which usually means the plant eats more. Also a plant can slow down eating or stop all together for a variety of reasons, such as stress or improper nute balance, ect. Sometimes maybe for just 5 minutes, other times hours. Add.27 will encourage the plant to continue eating like normal during these times. One of the things it does is coat minerals with a chelating agent. Think of a chelating agent as a sort of claw that latches onto the nutrients and carries it along. The plant can more easily uptake the chelated mineral so, basically it can eat more, faster. ( Not to be confused with a different type of chelating agent, which is meant to remove minerals from the bucket/plant.) Add.27 also encourages the plant to store little reserves of energy at the base of the leaves. If food becomes temporarily unavailable from the roots for whatever reason, the plant has plenty in reserve.
Liquid light is similar. In addition to supplying nutrients it also encourages the stomata to stay fully open. Stomata are like little mouths on the surface of the leaves that the plant uses to breath. The more efficiently a plant can breath, the more photosynthesis can take place. The saturator additive acts as a kind of chelating and wetting agent for the spray. Normally water beads and rolls off a leaf. Saturator will cause it to spread out and penetrate the surface. I only have a small garden, but I bought my 1 liter bottles 11 months ago. I spray every third day up until 3 weeks into bud. My bottle of LL is still 3/4 full, the saturator is a bit lower cos I use it for other sprays a well. So they are very economical. The results will speak for themselves. Be careful to mix as directed. Too much LL is counter productive.
Their reverse spray is also excellent. It wont do much for a true hermie, but plants that have developed male parts in response to stress are not true hermies. As long as the stress is corrected (light leaks, ect) reverse will cause the plant to revert to female, and cause any male parts to dry up and fall off.
I do not care for their rooting gel. It contains no artificial hormones and simply tries it's best to encourage natural rooting. For an accomplished cloner this is probably a fine product, but I personally prefer the help of rooting hormones. The APS spray is great for keeping clones healthy until they root, but it's optional. Again for an experienced cloner it is probably great, but I have better luck using wilt spray.
All DM products have an indefinite shelf life. It seems some hydro shops like to hike up the price for DM products. Shop around, they really aren't that expensive. My local shop wants $110 for the LL+Saturator combo, I got mine online for $60.