Welcome to our forum.
don't know about a septic forum - but my home is on a septic (uh the home uses a septic it's not really on it) and am very careful about what goes down the drain. You basically have 2 choices in managing your system - keep it as free from chemicals and non-organic particulars as possible to keep it a living "healthy" system OR have it pumped out frequently.
Is there such a thing as a 'septic system forum' anywhere? I'm very intersetd in this question since we are building a home on a septic tank and you can be sure we plan to put a spa in it! ( Uh, in the HOUSE, not in the septic tank...)I have no experience with life on a septic system...other than holding tanks which just get pumped out when full.