Give liquid RID-X a try after every dump.
<a href="http://www.amazon.com/gp/product/B004S6EG7A/ref=as_li_qf_sp_asin_tl?ie=UTF8&camp=1789&creative =9325&creativeASIN=B004S6EG7A&linkCode=as2&tag=aff iliatechie-20">RID-X Liquid Septic Tank Additive, 48 Fluid Ounce</a><img src="http://www.assoc-amazon.com/e/ir?t=affiliatechie-20&l=as2&o=1&a=B004S6EG7A" width="1" height="1" border="0" alt="" style="border:none !important; margin:0px !important;" />