If your EnsoPet is filling up too quickly this is likely due to the condition of your soil. Installing a second unit will address this issue.
By composting your pet waste with EnsoPet you will be greatly improving the quality of your soil due to the microbes present in the Starter. If your soil is in poor condition, this improvement may take several weeks. Using two units allows more time for your soil to get conditioned.
Adding some carbon rich organics such as dry leaves, fine bark, spent potting mix, to your EnsoPet will assist with improving the soil condition.
As the condition of your soil improves the breakdown of the pet waste will be quicker. Similarly, if you have a lot of pet waste or more than one pet, installing a second unit may be required. Or if you simply want to improve the soil in another part of your garden add an additional unit.