Pet Loo Replacement Grass (33" x 33") It's always a great idea to have some replacement Pet Loo Grass on hand to help with the cleaning process; while one is being cleaned, aired out and dried... use the replacement. Fits the Pet Loo for Small Dogs. Synthetic Grass There are many varying types of synthetic grass on the market. The Synthetic grass used for The Pet Loo is of optimum quality for drainage. After lengthy testing, we have ensured that the perforations on the base mat guarantee maximum drainage. Cleaning the Grass The grass only needs to be replaced when you feel it's necessary. For cleaning purposes pour warm water over the grass daily or alternatively lift it out and hose it down (in the shower if necessary) remove the grass to allow it to dry. For times when The Pet Loo is not in use (eg: overnight) remove the grass from The Base to air it out. Why Not Real Grasss The Pet Loo has chosen synthetic grass over real grass for the following reasons: 1. Urine kills real grass you will have to continually replace it 2. Not all apartments are in sun lit areas increasing the chance of the grass dying 3. The Pet Loo can live indoors grass will die with limited sun exposure 4. No need to water it especially with water restrictions 5. No need to constantly replace the grass synthetic grass will last years if taken care of properly 6. Pets won't bring the soil and grass inside if it were to get stuck to the bottom of their feet.