The most important property of container media is their structure - specifically, how much water and air they hold, and how long they are capable of holding it. You severely limit the ability of your medium to hold enough air when you use a soil comprised of all fine particles - peat, compost, topsoil, e.g.

Read more about container soils at the link below.

Al

Here is a link that might be useful: I'll take you to more about soils if you click me.

For most indoor gardeners, buying a packaged prepared potting mix is the most efficient method of selecting house plant soil. Potting mix is sold in verying sized packages so the gardener can use fresh without having to store over long periods which might affect the goodness for late use. Such commercially made soil can properly feed houseplants for limited times after which the gardener replenish the nutrients. Too, commercial grade soil has fewer pests and disease which can assure the user his plants are safe in it. Some soils have to be moistened before use. Squeezing a handful can inform whether this is necessary.

If the gardener wishes to make his own mix, there are specific reasons to use certain ingredients.
Garden loam or topsoil have particles of clay that hold fertilizing materials in an available state for plant roots. Sand (coarse), perlite and leaf mold hold air around the roots which is essential to good plant growth.
Charcoal bits keep the soil 'sweet'. Any soil you make yourself MUST be sterilized. Garden loam or topsoil may contain pests, weed seeds, or plant diseases. Putting seed into such soil mix without sterilizing is just inviting disaster.

The method of sterilizing is then up to the gardener but the kitchen oven comes into play and soil, being heated, can emit terrible odors that one should stop and think about before committing to do it.

Adding other materials to the mix is also up to the user but peat moss, because it holds moisture and improves the consistency of the soil, is always recommended. The amount of peat moss in relation to the other ingredients is also up to the maker but 50% is one percentage most advised.

Thanks for both replying. Wow, tapla, that link is intense. Interesting information, though.

Goren, well at least I know I was on the right track when I made the outdoor mixes (1/2 top soil and 1/2 peat moss). I've been doing that for years, and it's always been very good.

For the bugs, I did bring in a couple of pots that were a mix of 50/50 when the plants were placed outside (and they all seemed to do well with it.). I filled the bathtub with water, and submerged the plants in it for 20 minutes. Then, I rinsed them all off. I had read somewhere that it would kill any bugs in the soil. I just did it on Saturday. The plants I did it to seemed to do very well with that. Flushed out a big worm that I found swimming in the tub. LOL. Returned the worm to the outdoors (was still alive). Hopefully, that will have eliminated the problem for those.

But, I need to repot others, and I was hoping to come up with an inexpensive but good combot. I have a lot to repot.

Thanks for the info :)