Been on septic systems now for more than 32 years.
NC State University has done many years of extensive studies of all types.
In a nutshell, their findings:
A. All of those chemical additives are a total waste of money. Normal usage provides all of the bacteria necessary.
B. The only maintenance for normal usage is to have the tank pumped at least every five years (I went 14 years with no problems whatsoever before I found that out. I know people that have gone far longer). I have my tank pumped out every year ending in 0 or 5 to keep it "idiot proof "for me.
C. If you have trees or shrubbery over or near the tank or drainfield, flush a cup or two of copper sulphate crystals down the toilet about three times a year to keep the roots knocked back.
That's all that I do, and I never had any problems.
Consult your local Health Department septic system permitting technician. They can tell you what works best in your area, based on soil type, etc.
Here, they're the ones who custom-design each system based on the soil type of the lot and the planned usage based on number of bedrooms.
As advised, limit the amount of bleach, paint, solids (food particles, cig butts, etc.), grease, etc. and other non-biodegradeables.
Good Luck!
Mike
