Low Flow appliances and toilets can help your septic system last longer, which reduces your overall cost of ownership and costly repairs. You should replace older appliances, especially if your system is older or operating in duress. Using these appliances will decrease the amount of water used and will allow your system to process less water and recover quicker.
Look into Low Flow Dishwashers, Washing Machines and toilets. The two stage flushing toilets are an excellent option.
Lastly, water filtration systems should be updated as the new systems do not discharge as much water which keeps less water going to your septic system.