I asked Gary that question; as I recall I used the word "enzyme" as that's what I think some people put in their system. He said no not needed.
I took alot of notes and left with lots of great information. One is a maintenance journal he handed out. The scan I made, attached, got cut off a bit due to its size.
His color handouts with photos and technical data sheets detailing different systems were excellent. I'm sure he'd mail you a copy. Ask him to send what he gave us that night that was in the blue folder.
A little bit more of what he told us:
- Know where the edges of the leach field are;
- Know where your water well is in relation to the leach field; the law requires a certain amount, distance-wise, of separation of the two;
- Don't drive on a leach field;
- Water softeners are very bad but there is a way to deal with it;
- Chlorine and anti-biotic drugs that get flushed are also bad because they kill the critical bacteria needed for proper system functioning;
- Winterize the system if the home is used seasonally;
- Pump the tank from both ends regardless of what the septic tank pump guy may say;
- Spread out wash loads to prevent over-loading its capacity to process a given flow volume; as I recall if this is not observed raw sewage will get into the leach field;
- Consider a 2 chamber tank vs 1;
Lots more but you get the point. I haven't been to his website but here it is:
www.aosne.com
Hope this helps.