According to GoodNature website:
What is Core Aeration?
Grass roots need oxygen to function and in our heavy clay soils here
in Ohio, getting enough oxygen to the roots can sometimes be
difficult. With core aeration, we poke holes into your soil and pull
the cores out. Aeration helps lawns with thatch problems. It loosens
the soil to let nutrients work better; plus, it helps your lawn make
the best use of watering because an aerated lawn will retain more
water with less runoff. You do not want to aerate in the summer,
though. It is best to wait until the cooler weather (spring/fall)
arrives and the soil is a bit more moist. More information about Core
Aeration
What is Liquid Aeration?
Take the battle against thatch a step further and what you get is
liquid aeration. As the name suggests, this is a liquid application
that can be as effective as or even more than a traditional physical
aeration. Liquid aeration is an excellent tool because it can loosen
the soil deeper than core aeration can.
There are some liquid aeration type products on the market. We are
always testing and using new materials, but the basics are they
contain a few main ingredients. First, they contain some sort of
wetting agent to get the materials down into the soil. A wetting agent
can be made from natural materials like the yucca plant, or from a
more synthetic soap-like material. Either is probably fine. Secondly,
the product should contain food for microbial life, typically humates
and maybe kelp. Finally, a good liquid aeration product should contain
enzymes or bacteria that are specifically designed to break down
thatch. Sometimes the thatch decomposition product is in a separate
package and requires its own application. At the time of this writing,
we are recommending Aerify Plus and Biological Dethatcher, both
available on our store website. More information about Liquid
Aeration
What to Choose - Liquid or Core Aeration?
Core Aeration will have a more immediate impact on your soil and the
look of your grass. But, the effects are not very long lasting. The
liquid aeration will NOT have such an immediate impact on your soil
but the effects are longer lasting and accumulative so they build over
time. The exception would be if your soil is very compacted or you
have a significant amount of thatch, which would be anything over 1/2
inch. In that case, we would recommend using both Core and Liquid
Aeration to help make a long term impact. You should have the Core
Areation before the Liquid. This will help the Liquid Aeration
penetrate the lawn so that it can work better and faster.