YES!!! I LOVE that show! :D

It's hard to catch the show with any regularity though. :(

A tip given to me by the Honey Dipper (as they are sometimes called), is to take a long stick (longer than your tank is deep) and stick it in the tank.

If the stick does not fall over on its own, it is time to pump it.

Besides that, Keep grease out of it, and limit the amount of garbage disposal use.

You usually have two layers to be concerned about. The top layer (if you have one) is scum, and is hopefully not solidified. The bottom layer is the one that is usually thicker, and is the one that needs to be pumped. One way to increase digestion would be to airate the solids on the bottom (preferably in the middle of the night, so that the solids can settle again before you start adding "liquids" to the system)

Older Systems have drain tiles...they usually work well, unless they get driven over and crack, or there are roots nearby, and disturb the tiles so that soil is introduced thereby clogging up the works. Never systems have perforated plastic pipe with a synthetic sock over them...a bit more forgiving with roots and heavy things landing on them (like a car), although they are not invulnerable. Steel tanks should be checked for corrosion. Concrete Tanks should be checked for deterioration (sewer gasses like to eat concrete)...you don't want your tank crumbling to pieces. New tanks are usually fiberglass, although sometimes you still hear of concrete tanks being used here and there.

All this is probably way more than you wanted to know. :D

Never
 

so, soooooo right. the answer could be never if the tank is properly connstructed in certain soils and if you use it properly... no grease and all that above...

you can also get a block of pure yeast and dump it down the toilet (crumble it up first!) it's way cheaper then rid-x and just as effective...

Our local old wives tale around here is NOT to use those additives. We've just used a package of baking yeast every now and then.
NEVER use powdered laundry or dishwasher soap. It'll re-condense in your drain field and clog things up big time. Liquid soap only. And keep your bleach use to a minimum.
More factors to the longevity is the type of soil you have, and if you have a pressure system. Pressure systems, like we have, keep things flowing better. And we have very rocky soil here. 15 years, and no prob's yet.

I was thinking about this $hit last night and I'm wondering about the efficacy of yeast down the tank.

To my knowldge, all yeasts are facultative anerobes that metabolize simple sugars. They are unable to metabolize starch or more complex carbohydrates like cellulose or fats nor the chemically quite distinct proteins.

Simple sugars are water soluble and metabolized by dang near every living creature and so they should never be a problem in a septic system.

What you need is a wide range of bacteria species that are variously capable facultative anerobiosis and obligate anaerobes that are capable of metabolizing all of the various constituents of doo-doo in the presence of such insults to itty-bitty life as soaps, detergents, and cleaning chemicals.

Back in my pseudo-hippy days I designed and built a two-stage septic system that worked pretty well. The first stage was twice the volume of the second and took toilet water and sink water from the kitchen (except for cooking oils and fats and scraps, which went variously to dogs and chickens). The second tank received lavatory water and clothes washer water as well as the mid-level fluid from the first stage. My theory was that the first stage needed more time in anaerobic decomposition and would displace fluid to the second stage that was at least partially digested. The second stage was mostly aerobicly decomposed. Water from this tank was taken from nearly on the bottom of the tank and sent to the field lines. Since I lived on a clay hill, I hade a huge field line system, over which I grew lawn. Lush, green lawn. In stripes.

Pressure systems are close to what you're talking about. I have 2 tanks also. The first is the settling tank, the second takes the overflow from the first, and after it fills up to a point, the pump sends it out to the drain field. Works pretty well.
Oh, and yeah, I have the green strips out in the yard during a long hot summer :D

The older detergents that contained phosphates were the worst thing for septic tanks. The solids would continue to build until they blocked the flow into the leach lines. (Don't ask me how I know.)

As you have seen, the responses are all over the lot on the issue of when to pump. You have a good test period since it was last pumped seven years ago. I would have it pumped again to see how it did over the past seven years. This should tell you if it needs to be pumped every (fill in the blank) years or if you even need to pump it at all.

Because our current system isn't in use for six months during the summer, I put a container of Roebic in it every fall. Not sure it is necessary, but I do it anyway. The tank hasn't been pumped since we bought the place ten years ago and it is doing just fine.

I have a friend whose wife isn't too careful about what she puts down the drain (and they have a garbage disposal too) and his rule of thumb is to have the tank pumped every presidential election year. (NOT a political statement, just an easy way to remember to do it every four years....)

Wes

Some outstanding advice offered here and a lot more knowledge of that end of the business than I ever thought was possible. :D Thanks to all. I will pump!